Frequently asked questions

Frequently asked questions about the Publish or Perish software

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Top questions

Search questions

Missing papers or references

Duplicate entries

Other search and results issues

Common errors

Other software issues

Have an important question that is not here?

Please send us an email and explain why you think this question needs to be covered in the FAQ. In the meantime you are likely to find the answer to your question in the Publish or Perish Manual or the Publish or Perish Tutorial.

Top questions

How to cite the Publish or Perish software

If you are using the Publish or Perish software in one of your research articles or otherwise want to refer to it, please use the following format:

Harzing, A.W. (2007) Publish or Perish, available from

Why use Publish or Perish rather than online portals?

Here's the response of one of our users; we couldn't have said it better ourselves:

Searching for publications through internet portals is a pain as they are typically quite slow, all have different interfaces that aren't particularly intuitive and don't help at all to keep track of the searches you have already done. PoP solves all the issues above, it is both easier and faster to use than web portal alternatives. With PoP I feel much more confident that I can perform a systematic review of available literature on a topic when using PoP. I also really like how the results from a search are displayed; it is easy to rank them and/or filter them by a wide variety of criteria and this is really helpful.

Author disambiguation (getting only the author you want)

This is a very tricky problem. Even commercial databases like Thomson Reuters Web of Science (ISI) have problems with this, see:

  • Harzing, A.W. (2016) Health warning: Might contain multiple personalities. The problem of homonyms in Thomson Reuters Essential Science Indicators, Scientometrics, vol. 105, no. 3, pp. 2259-2270. Available online...

However, there is a lot you can do to get the right author by "smart searching". Have a look at the Publish or Perish tutorial which has lots of tips and tricks. In particular, read the pages on author disambiguation.

Where are "any of the words", "all of the words" and "none of the words" fields in PoP7?

We removed these fields [specific to Google Scholar] to allow for a more flexible and repeatable search across data sources. However, these kind of searches are still possible in the new Title words and Keywords fields by using the Boolean operators OR, AND and NOT [in capitals]. Please note not all data sources allow all operators.

For more information on this see General/keyword search in the documentation.

Can you bring back the subject categories?

Sorry, it is Google who removed them!

Many longstanding users are asking to reinstate the subject/discipline categories. Removing them was certainly not by choice: Google Scholar abolished them in 2012; they claim they were not used by most users.

For more information on this see Google Scholar: missing subject areas in the documentation.

Why do you give me these stupid CAPTCHAs?

We don't issue CAPTCHAs; Google does.

Again, remember that Publish or Perish is an interface to Google Scholar and other data sources. We have absolutely no interest in blocking your use of Publish or Perish. On the contrary, we do our best to comply with the various data sources' requirements in terms of query rates and query volumes.

For Google Scholar this may occasionally cause the appearance of a CAPTCHA to verify that you are a human, not a robot, if you do regular searches. When that happens, Publish or Perish displays the CAPTCHA to let you solve it, then uses the resulting Google Scholar access token to continue with your search.

In extreme cases Google might return an HTTP status code 429 (Too Many Requests); in that case you will have to refrain from using Google Scholar for 24 hours or so before retrying.

For more information see Google Scholar: Captchas.

Please note: Google Scholar Profile searches are not subject to the same captcha requests; the other data sources in Publish or Perish do not display CAPTCHAs either, but may impose their own limits in other ways.

Why is my h-index in PoP different from ... [Google Scholar,Web of Science, Scopus]?

  1. Provided you use exactly the same search syntax in both, your h-index in PoP and GS will identical (see Accuracy: PoP vs GS).
  2. The Web of Science (ISI), Scopus, Google Scholar and Microsoft Academic have different levels of coverage for different disciplines. For a comprehensive comparison, please see: Microsoft Academic: is the Phoenix getting wings?

For detailed information see also:

Help! Microsoft Academic is no longer working

Microsoft Academic discontinued API access after 31 December 2021. For details see the Microsoft announcement here. The MA web interface has likewise been discontinued and now redirects to the Microsoft home page. We have maintained Microsoft Academic documentation for heritage projects.

I'm getting an "Invalid certificate" error when performing a query

This may occur in Publish or Perish version 5.x if you are still using Windows XP. You will typically see a dialog box similar to the following:

Invalid certificate warning

The underlying cause of the error message is a mismatch between the SSL certificate that Publish or Perish expects for its connection to Google Scholar and the actual certificate provided by Google Scholar's server.

It appears that Google sends an SSL certificate for instead of or * for requests that originate from older versions of Internet Explorer (such as IE8 that Publish or Perish uses on Windows XP, because no later versions than Internet Explorer 8 are available for Windows XP).

A more sinister potential cause is that you are using a web proxy (perhaps your organisation's) and that its SSL certificates are invalid or even compromised, or that you are using an anti-virus tool or similar security program that actively intercepts HTTPS connections and offers its own SSL certificates.

There are several (partial) solutions to this issue, depending on the exact cause. You will have to try them each until you find one that works.

Before you start, make sure that you are using Publish or Perish 5.27 or later. We have added some automatic mitigations for the certificate problems in this version of Publish or Perish.

  1. Simply click "Yes" when asked if you want to proceed. This doesn't solve anything, but it might get you through. It might be necessary to retry your query after clicking Yes for the first time.
  2. Make sure that you are NOT using a proxy. Proxies are often badly configured, particularly when you try to perform HTTPS (secure) web connections. You can find the applicable proxy settings, if any, by choosing Tools > Internet Options from PoP's main menu, then going to the Connections tab, clicking on the LAN settings button, and making sure that no proxy is configured.
  3. Change the Google Scholar URL (if you are trying to perform a Google Scholar lookup, and not Microsoft Academic) to use plain HTTP (insecure) instead of HTTPS (secure): choose Tools > Preferences on the PoP main menu, go to the Google Scholar tab, and edit the Query URL field so it starts with http:// instead of https:// This won't work for Microsoft Academic --which always uses HTTPS-- and may not work much longer for Google Scholar, because Google is also transitioning to HTTPS-only.
  4. Upgrade your system to at least Windows 7 and at least Internet Explorer 11, and make sure that all "recommended" Windows Update updates have been applied.

Search questions

Why have Google Scholar queries become so much slower?

To avoid exceeding the maximum acceptable Google Scholar request rate.

In February 2013 Google Scholar reduced the maximum number of results per request from 100 to 20. Later it reduced this further to 10 results per request. This means that Publish or Perish now has to perform up to 10 times as many requests per query in order to show the full results.

  • More data requests mean that Publish or Perish hits the maximum number of requests that Google Scholar allows per hour sooner.
  • If the number of requests exceeds the maximum that Google Scholar allows, your IP address will be temporarily blocked by Google Scholar. This block can last for up to 24 hours.
  • To avoid hitting the maximum allowable request limit, Publish or Perish now uses an adaptive request rate limiter. This limits the number of requests that are sent to Google Scholar within a given period, both short-term (during the last 60 seconds) and medium term (during the last hour).
  • To achieve the required reduction in requests, Publish or Perish delays subsequent requests for a variable amount of time (up to 1 minute). The higher the recent request rate, the longer the delays.

The net result is that queries will take longer than before. The alternative is being blocked by Google Scholar for up to 24 hours. We consider the relatively short delays during queries as the lesser evil, hence the adaptive rate limiter. If you perform queries with few results or only occasionally, then the request rate limiter will have little or no effect on the query time. In this case, the required delays are short or non-existent, and Publish or Perish will retrieve result pages as fast as it did in the past.

However, if you perform queries that yield many results (several hundred or more) or issue a number of queries in short succession, then the request rate limiter will insert progressively longer delays to keep the overall request rate within acceptable limits. If you want to avoid this, then the best remedy is to spread your queries over the day.

To use the adaptive request rate limiter, make sure that:

Publish or Perish only searches for English names?

Not so; you can search for any name (or other words) regardless of the language.

Publish or Perish submits your query properly encoded to each data source, so as long as a data source has matching data, the information will be found. However, it can be that the data source's coverage of non-English source material is less complete than that of English.

How do I search for names with accents?

If you are looking for an author whose name contains accented letters, then it might help if you include several variations of the name, both with and without accents, and also with the accented letters missing. The reason for the latter is that some data sources cannot handle accented letters and either omit them or map them to the closest accent-less equivalent.

For example, to search for someone with the surname Veríssimo (note the accent on the first 'i'), use the following names in the Authors field:

Veríssimo OR Verissimo OR Verssimo 

I have published under several names. How do I find all my papers?

By using an OR query in the Authors field and specifying all names under which you published. For example, if you changed you name when you married, then use a query that includes both your maiden name and your married name.

How do I exclude self-citations from the results?

You cannot do so directly.

Publish or Perish uses a number of data sources and identifying self-citations requires numerous follow-up queries, potentially exceeding the acceptable number of search requests for the data sources. For that reason, Publish or Perish implements first-level queries only. If you want to exclude self-citations, you must identify them yourself and then exclude them from the Results list by clearing their check boxes.

Can I use Boolean expressions in an author search?

Yes to some extent. The following seem to work with the Authors field:

  • To perform an "and" search, enter multiple author names separated by AND [not supported in Crossref]
  • To perform an "or" search, enter multiple author names separated by OR
  • To perform a "not" search, enter multiple author names separated by NOT [not supported in Crossref or Microsoft Academic]

Note that if you use initials or given names, you need to put quotes around the name, e.g. "A Harzing". Also note that the Boolean operators need to be in UPPERCASE to be recognized as such.

How do I search for all publications by authors affiliated with <my university name> in Google Scholar?

You cannot do so directly.

Google Scholar does not have a affiliation field in the same way that some other data sources have. Hence a search like the one you describe will not always give reliable results. You can try to search with your university name in the General Search Keywords field (for details see General Search: Institutions), but this will match the name anywhere in the documents (not only as author affiliation) and for some universities is not comprehensive. Currently, we therefore cannot recommend this type of analyses with Google Scholar beyond very general curiosity driven experiments.

Other data sources allow for affiliation searches with varying levels of reliability.

For more information see Affiliation search in the documentation.

Can I use Publish or Perish to identify the main publications in a certain area?

Yes, up to a point. Search for relevant keywords in the Keywords or Title words field (see helpfile for description of these fields). The most cited results are (probably) the main publications.

Can I use Publish or Perish to identify the main authors in a certain area?

Yes, up to a point. You can find the main authors (or at least the most cited ones) in both a subject area and in a specific journal.

In a subject area: Search for relevant keywords in either the Keywords or Title words field field (see helpfile for description of these fields).

In a specific journal: Search for the relevant journal in the Publication name field. You may want to restrict your search to a certain period by using the Year of publication fields.

The most cited results belong to (probably) the main authors in the field or journal. You can also sort the results list on the Authors column; this groups papers by the same author together and may tell you at a glance who the most active authors are in a given area or journal.

Why do I get so many irrelevant results?

Possibly because your search is overly broad and you only see a tiny subset of the results.

Example: if you search for all papers published in:

"Strategic management journal" OR "Academy of Management Journal" OR "Journal of Business Venturing" OR "Entrepreneurship Theory and Practice" OR "Academy of Management Review" OR "Administrative Science Quarterly"

then there are hundreds of thousands (for some data sources perhaps even millions) of potential matches. However, all data sources restrict the maximum number of results that they return to a much lower number, typically 200-1000. You will therefore only see a miniscule portion of the matches and probably not what you are looking for.

To resolve this, make you search specific. Only search for one or a few journals (for example) at a time, and even then restrict the potential number of results by using year ranges, adding keywords, or adding specific author names.

Alternatively, and in particular if you perform a Google Scholar search, you may get too many results or irrelevant ones because your search contains too many terms and Google Scholar ignores the surplus (empirically, anything beyond the first 250 or so characters) and returns results based only on the first few search terms. If your search contained additional, more specific terms, then those will simply be ignored, causing irrelevant results to be shown.

Other data sources than Google Scholar usually have higher limits on the length of the search terms or produce a more or less meaningful error message if you exceed their limits. However, you should still heed our advice and make your search specific because overly broad search terms may cause internal overflows in some of the other data sources, causing them to return zero results or another error message even if there ought to be a reasonably small set of results.

How do I get more results than the 200 or 1000 that Publish or Perish allows?

Publish or Perish does not by itself limit the number of results that you will receive. Any limits are imposed by the original data source:

  • Crossref: 1000
  • Google Scholar: 1000
  • Google Scholar Profile: 1000
  • Open Alex: 1000
  • PubMed: 1000 (199 for author and affiliation searches; 199 or 398 for some title and keyword searches, exact details unknown at present)
  • Scopus: 200
  • Semantic Scholar: 1000
  • Web of Science: 200

Remember: Publish or Perish is only an interface to these data sources!

The other thing to consider is this: do you really need more results? Will you really use all 200 or 1000 results, or even more? Would it not be better to make your search more specific, so you will only get the results that are really relevant to you?

If you really, positively, absolutely, need more than the number of results that the data source allows for any given search and you cannot make your search more specific, then partition your search by using non-overlapping year ranges. Publish or Perish makes this easy: when you click the New button, the new search will be preset to the same parameters as the original search, so all you have to do is adjust the year range in the new search.

Missing papers or references

Publish or Perish doesn't find any of my papers!

Assuming that you really have published scholarly papers, there may be several reasons why Publish or Perish doesn't return any results for your name.

  • You spelt your name incorrectly. Correct any typos and try again.
  • You entered your given names in full instead of as initials. This may find some papers, but many publishers only list the author's initials and a full name search misses those papers. To be on the safe side, try using both full names and initials in a single query, like this (the "quotes" are highly recommended): "A Harzing" OR "Anne-Wil Harzing"
  • Your papers are not available online, neither through your publishers nor through your own web pages. If that is the case, then Google Scholar and Microsoft Academic do not know about your papers.
  • You published in a language other than English. Google Scholar's and Microsoft Academic's coverage are improving, but non-English publications still are underrepresented in the results.

Here are more search tips and an explanation of Google Scholar limitations.

Can you please add/correct [...]?

Sorry, we do not maintain a publication database.

Publish or Perish is an interface to the various data sources (Crossref, Google Scholar, Google Scholar Profiles, Microsoft Academic, PubMed, Scopus and Web of Science). We do not sit up at night entering your publications in a "Harzing database" as some users seem to think :-).

Some data sources collect their data by scraping publishers web sites (for example, Google Scholar and Microsoft Academic do so), while others rely on data entry by publishers or authors, or use some other form of curation (for example Crossref, PubMed, Scopus, and Web of Science).

Regardless of the method used for data collection, occasional errors will and do occur in the external data sources, so you will need to contact the individual data sources for any problems with your publications or citations.

For more information, see the Accuracy page of the Publish or Perish manual.

My paper/book does not appear in Publish or Perish. Can you correct this?

Sorry, no. We do not personally maintain a database of academic publications.

Publish or Perish uses a variety of data sources to obtain its raw data. The quality and scope of their databases vary; some data sources do automatic processing, others (like Web of Science or Scopus) perform a mixture of automatic and manual curation. However, none of the data sources are perfect and occasional errors or omissions do occur.

This may be due to:

  • Papers that are not (yet) available online. This includes many older papers.
  • The nature of the publication: some books and other non-journal publications might not be accessible to the data source, or simply not included in its corpus.
  • Publishing in journals to which the data source in question has no access because of the journal publishers' policy or publishing agreement.

For more information limitations of Google Scholar, see the Google Scholar pages in the PoP tutorial.

My journal does not appear in Publish or Perish. Can you correct this?

Sorry, no. We do not personally maintain a database of academic journals.

Publish or Perish uses a variety of data sources to obtain its raw data. The quality and scope of their databases vary; some data sources do automatic processing, others (like Web of Science or Scopus) perform a mixture of automatic and manual curation. However, none of the data sources are perfect and occasional errors or omissions do occur.

If a particular journal does not appear in a data source, that could be due to one or more of the following reasons:

  • The journal in question is not accessible to the data source in question because of the journal publishers' policy or publishing agreement. This is likely to apply to automated data sources such as Google Scholar and Microsoft Academic.
  • The journal in question is not included in the data source's corpus. This is likely to apply to curated data sources such as Scopus and Web of Science.

Whatever the exact cause, you will need to contact both the journal's publisher and the owner of the data source (remember, that is not us!) to get them to sort things out between them.

I am a journal editor. How do I get Publish or Perish to list my journal?

We do not personally maintain a database of academic publications.

Publish or Perish uses Google Scholar and Microsoft Academic data to calculate its citation metrics. You will therefore need to contact them to include your journal. Once they do, Publish or Perish will use the same data.

The number of citations for my paper is too low. Can you correct this?

Sorry, no. We do not personally maintain a database of academic publications.

As indicated elsewhere on the this website, Publish or Perish uses Google Scholar and Microsoft Academic data to calculate its citation metrics. Their processing is automatic (unlike ISI's or Scopus' that involves manual handling and checking, with the associated price tag) and hence occasional errors or omissions do occur.

This may be due to:

  • Incorrect or sloppy referencing of your paper by others. Try to find the referencing works to see if this is the case.
  • References in older journals or in journals that are not available online. Google Scholar only uses online information; if your paper or the references to it are not online, they will be omitted.
  • References in journals to which Google Scholar or Microsoft Academic has no access because of the journals publishers' policy.

For more information limitations of Google Scholar, see the Google Scholar pages in the PoP tutorial.

Publish or Perish does not find all my publications, but Google Scholar does. Why?

Publish or Perish uses the Google Scholar Advanced Search options. This is not the same as the standard Google Scholar search box. The search results might differ for one or more of the following reasons:

  • A Google Scholar general search returns papers in which the search terms that you entered appear anywhere - as author, title, or even in the contents. In contrast, a Publish or Perish search is more specific and will only return papers that match in the fields that you specified: author names only in the author field, title words only in the title, etc.
  • Perhaps Google Scholar did not classify your name correctly as an "author", but somewhere else (for example as part of the title - this is usually due to sloppy references to your article). A Google Scholar general search will still include the paper, but the more specific search that Publish or Perish uses will not if it does not find your name in the "Author" field.

For more details on this, please see Accuracy of the results.

Why do some results have truncated (...) fields, such as "International Journal of ...."?

In the early days, Google Scholar provided complete records for authors and the publication source. However, since about 2012 both fields are regularly truncated, with part of the field replaced by dots […..]. We do not know why Google Scholar decided to introduce truncation. It might be related to the “space” available in these fields. Unfortunately it can make finding the right publication very frustrating, both in the Google Scholar interface and in Publish or Perish. For more details see: Google Scholar: Truncation

Workaround: Use Publish or Perish to generate a list of articles (including truncated entries) and save the results as BibTeX, EndNote, or RIS/Reference Manager (Select the Query, Right-click and click Save to File). Import this file into a new folder in Mendeley, right click and select ‘update details’. This completes most of the truncated entries. Please note that this is limited to entries where Mendeley can find the full entry and is thus more likely to work for traditional publications such as journal articles. [Thanks to Alex Harrison at the European Society of Endocrinology for this tip]

Duplicate entries

My paper appears as several different entries in Publish or Perish. Can't you combine these?

Publish or Perish uses Google Scholar and Microsoft Academic data and these data occasionally split what you know is a single paper into multiple entries. This is usually due to incorrect or sloppy referencing of your paper by others, which causes Google Scholar to believe that the referenced works are different. As of Publish or Perish release 3.0.3780 it is possible to merge duplicate results manually in the results list.

My paper is duplicated under different languages of the same journal. Can't you combine these?

Publish or Perish uses Google Scholar and Microsoft Academic data and these data sources will typically consider different language editions of what you know as the same journal as separate journals. For example, English and French versions of a Canadian journal (or merely of different versions of the journal title) will typically be considered to be different. As of Publish or Perish release 3.0.3780 it is possible to merge duplicate results manually in the results list.

Other search and results issues

How do I improve the accuracy with which Google Scholar lists my papers?

In general, this is rather difficult, because a lot depends on the accuracy with which your papers are referenced by others.

However, if you have separate web pages for each of your papers, then Google Scholar advises that you can add several meta tags to your pages to help Google's crawler to list your paper. In particular, they recommend using the following tags (replace the content="..." bits with your own information):

<meta name="citation_journal_title" content="Journal Name">
<meta name="citation_authors" content="Last Name1, First Name1; Last Name2, First Name2">
<meta name="citation_title" content="Article Title">
<meta name="citation_date" content="01/01/2007">
<meta name="citation_volume" content="10">
<meta name="citation_issue" content="1">
<meta name="citation_firstpage" content="1">
<meta name="citation_lastpage" content="15">
<meta name="citation_doi" content="10.1074/jbc.M309524200">
<meta name="citation_pdf_url" content="">
<meta name="citation_abstract_html_url" content="">
<meta name="citation_fulltext_html_url" content="">
<meta name="dc.Contributor" content="Last Name1, First Name1">
<meta name="dc.Contributor" content="Last Name2, First Name2">
<meta name="dc.Title" content="Article Title">
<meta name="dc.Date" content="01/01/2007">
<meta name="citation_publisher" content="Publisher Name">

If you don't know what meta tags are, then this information is not for you.

Can Publish or Perish automatically identify authors in the list of results?

No; this is too difficult with the current results from Google Scholar. Here is what the Publish or Perish developer had to say about this when he investigated the issue in March 2009:

Hi Anne-Wil,

I have looked into the weighted author contribution issues that you
raised, and here are my findings.

(a) The actual calculations are simple enough and not a limiting

(b) The trouble lies with reliably identifying and tracking individual
authors in a set of results.

Let me clarify point (b). In a typical set of Publish or Perish search
results, the Authors field of each results item contains a semi-formatted
list of author names.

It is possible, up to a point, to split each author list into its
separate author names. We already do so for the purpose of the
Individual h-index, and also to provide an overview of papers with 1,
2, 3, etc. authors. For the Individual h-index this is sufficient,
because each author receives the same weight (namely, 1/n if 'n' is
the number of authors for that paper).

However, reliably recognizing and tracking a given author, as would be
required for any scheme that assigns unequal weights to authors based
on their position in the authors list, is a different matter.

The Google Scholar data contains a lot of noise (usually through no
fault of Google, but simply the result of sloppy or inconsistent
referencing by humans) that makes this harder than it appears.

To give just one example: an author search for "a harzing" [sic]
results at the moment [March 2009] in 158 papers, most of which appear
to be (co-)authored by you. Looking at the results, your name appears as:

  A Harzing
  AK Harzing
  AW Harzing
  AWK Harzing
  AWIL Harzing

...but in some of the results it doesn't appear at all. Now you and I
may know that all these variations refer to the same person (you), but
this cannot be universally assumed:

- For an author search, the search phrase "a harzing" might give a
clue, but only if you are prepared to follow English naming
conventions of one or more initials followed by a surname. For other
cultural conventions, this might not be appropriate.

- What if the author search phrase used several author names, like:

    "a harzing" OR "c kulik"?

- For non-author searches, you don't even have this starting point.

- For any searches, you might want to extract a list of all author
names from the results, but then the matching process across the
results set is even iffier -- perhaps not for semi-unique names such
as Harzing, but certainly for the Smiths and Browns of this world.

- And then there are completely garbled results, like this one from
the same sample:

  Authors: AW Harzing, R Wal
  Title: van der (2008). A Google Scholar h-index for journals...

This refers to the article you co-wrote with "R van der Wal", but no
algorithm would be able to find this person in the Authors field.

Therefore, to get this to work, we would have to implement some sort
of user interface that allows the user to indicate which authors
should be combined. This in itself is not rocket science, but it will
take more development work to make it usable to the average user than
we have available at the moment.

Why does Publish or Perish always count years until the current year, and not the indicated period?

Situation: You have just done a search (any search) with specific start and end years, for example from 2000 to 2005. However, the results do not show "6 years active" as you expected, but "10 years active" (if the search is done in 2009). What's going on?

Answer: The search period (2000 to 2005 in the example) restricts the original publications. It does not restrict the citations.

Regardless of the start and end years in your query, the results will always show the citations until the present day, give or take a few weeks. And because Publish or Perish shows citation statistics, we must count all years from the start year until the present day.

Before you ask: No, Publish or Perish does not have control over this aspect of the results; it's Google Scholar that provides these data.

What does the Rank column indicate?

"Rank" is simply the order in which the data source returned the results, with higher-ranked (i.e., lower-numbered) items returned before lower-ranked (i.e., higher-numbered) ones.

Depending on the data source, this usually means that the higher-ranked ones were a better match for the search terms, which is not the same thing as being more highly cited (in the "Cites" column). On the other hand, some other data sources do return more highly cited results first, so for those data sources the "Cites" and "Rank" orders more or less correspond.

Common errors

What does error 13 (Access denied) mean?

This means that the Google Scholar response to your search request contained a refusal to accept further requests from your IP address. This is usually caused by an excessive number of prior searches. Google Scholar will normally lift the block after 24 hours or thereabouts.

Publish or Perish tries to minimize the chances of this happening in various ways:

  • It limits the rate at which search requests are submitted to Google Scholar. This happens adaptively: the first few requests are submitted in quick succession, but subsequent requests are slowed down to keep the request rate within bounds.
  • It responds to Google's request for human identification and presents the CAPTCHA challenge from Google if Google detects unusual activity from your IP address. You can then solve the CAPTCHA and submit it to Google. If you solved the CAPTCHA correctly, then Google will allow further access from your Publish or Perish session.

Under some circumstances, particularly when you submit multiple searches after another and request all available results (usually 1000) for each search, solving a CAPTCHA is not enough to prevent an Access denied error.

If that happens and your access is blocked for longer than 24 hours, then you could try to reset Publish or Perish's state according to the following instructions.

(Note that this is only a temporary workaround; if you keep submitting too many search requests, then Google Scholar will block your system again. Consider reducing the number of search results for each query; you probably don't need all 1000 or so results anyway.)

On Windows systems:

  1. Exit Publish or Perish (Alt+F4)
  2. Use File Explorer to navigate to the %APPDATA%\Publish or Perish\cache folder.
  3. In this folder, delete the gscholar.cookies file.
  4. Enter the gscholar subfolder.
  5. In this subfolder, delete the 2-3 most recent .dat files (sort the files by date first).
  6. Start Publish or Perish again. Your Google Scholar searches can now be resumed.

On macOS systems:

  1. Quit Publish or Perish (Command+Q)
  2. Use Finder to navigate to the ~/Library/Application Support/Publish or Perish/cache folder.
  3. In this folder, delete the gscholar.cookies file.
  4. Enter the gscholar subfolder.
  5. In this subfolder, delete the 2-3 most recent .dat files (sort the files by date first).
  6. Start Publish or Perish again. Your Google Scholar searches can now be resumed.

What does error 514 (No matching data found) mean?

This means that the response to your query contained no entries. Possible causes include:

  • A query that did not match any papers. Try changing the query parameters.
    • Tip 1: The API of some data sources does not allow the use of the words "and", "or", "not" or other common/stop words in a keyword or title search. Try omitting these words.
    • Tip 2: If you want to use Boolean operators, you will need to use capitals e.g. AND, OR, NOT. For further details on search syntax see: General/keyword search
  • Your Internet connection does not work.

What does error 522 (Invalid data) mean?

This means that the data source's response to your query contained no recognizable data. Possible causes include:

  • The data source's output format has changed.
  • Your Internet connection does not work.

While we try to adapt as quickly as possible to changes in output formats, there may be a delay of a few days after a data source introduces a new format.

Furthermore, even after we release a new version of the software, you must update your own copy of Publish or Perish to receive the benefit of the new software version. You can do so through the Publish or Perish web page, or by using the Help > Check for Updates command from the Publish or Perish main menu.

After updating the Publish or Perish software, retry the query using the Search Direct button (instead of Search). This retrieves fresh query data, which might resolve the problem.

If nothing else helps, then please lodge an error report to Publish or Perish technical support as follows:

  1. Repeat the query that failed.
  2. Choose the Tools > Report Error command from the main menu.

This generates an error report (a plain text file) called PoPError.txt that you should attach to your email to the Publish and Perish support address. We need the information in the error report for an accurate diagnosis.

What does error 1027 (Server error) mean?

Sometimes you see an error message like the following*:

*The screen shot is from Publish or Perish 6.x. In Publish or Perish 7.x the same error may occur, but with numeric code 1027 instead of 12152.

Google Scholar error 12152

The second part of the error message (We're sorry but it appears that...) originates with Google Scholar. It is occasionally returned by Google Scholar, and always (to our knowledge) at the end of a long search -- like the results 980-1000 of a search.

There is nothing that we can do about this and, despite appearances, there doesn't seem to be anything that Google does about it either, so you will just have to live without the final 20 or so results of that search.

What does error 1028 (Invalid client request) mean?

If you see an error 1028: Invalid client request then the data source found some sort of syntax error in the query that Publish or Perish submitted. There is usually some additional information about the nature of the error displayed as well; if this doesn't make the problem and its solution obvious, then please submit an error report.

What does error 1150 mean?

This error code appears when Google Scholar sends a CAPTCHA in response to a request and your system contains an out of date version of Internet Explorer. Solving the CAPTCHA requires a recent version of Internet Explorer (IE8 on Windows XP and IE11 on all later Windows versions). The Wine emulation of IE is insufficient for this and will also cause this error message.

You can do one of the following:

  • On a real Windows system, run Windows Update to install the latest version of Internet Explorer (in fact, PoP will offer to start Windows Update for you); or
  • Use a different data source within PoP (we support six different sources, most of which are free or require a free subscription key); or
  • Wait 3-4 hours before resuming your queries; or
  • Continue on a full Windows system if you are currently running on Wine. This can also be a virtual machine; we use VirtualBox on Linux and macOS (both iMacs and MacBooks) with Windows 7 inside.

What does error 1544 (Authentication required) mean?

This error code appears under the following circumstances:

  • The current data source requires an API key or login account, but none is available; this applies to Microsoft Academic, Scopus, and WoS, and will be indicated in the error details.
  • Your Internet connection requires authentication, usually because of a proxy server.

In the case of a missing API key or missing login credentials, Publish or Perish will automatically display a dialog box that allows you to enter the required information or apply for an API key as appropriate.

If proxy authentication is required, then you should either use your regular web browser to authenticate yourself to the proxy, or disable the use of a proxy for Publish or Perish.

On Windows, you can change the proxy settings as follows.

  1. Start Publish or Perish
  2. From the Publish or Perish main menu bar, choose View, then choose Internet Options. This should show the "Internet Properties" dialog box from Windows.
  3. In the "Internet Properties" dialog box, click on the "Connections" tab, then click on the "LAN settings" button. This should open the "Local Area Network (LAN) Settings" dialog box as shown below.
    Windows proxy settings
  4. Make sure that the "Use a proxy server..." checkbox is clear. If it is already clear, then also make sure that the "Automatically detect settings" box is clear as well. (In the attached screen shot, this box is checked -- but uncheck it if the problem persists.)
  5. Click OK to close the "Local Area Network (LAN) Settings" dialog box, then click OK again to close the "Internet Properties" dialog box.
  6. Retry the search with Publish or Perish.

Updating Publish or Perish fails with error code 740

This occurs when you try to update the Publish or Perish software on Windows XP and later (including Vista and 7). The full error message is:

Error 740 while updating the software.
The required operation requires elevation.

This is caused by an old version of the update software; it is not related to the Publish or Perish software itself. To resolve it, do the following.

  1. Close any running instances of the Publish or Perish software.
  2. Download the latest version of the software from the Publish or Perish page. This will result in a file called PoPSetup.exe on your computer.
  3. Run the PoPSetup.exe program that you just downloaded. This will update the Publish or Perish software on your computer to the latest version.

This procedure needs to be performed only once; later versions of the Publish or Perish updater no longer cause the error message.

Installation under Wine on Linux fails with "Call to unimplemented function"

This is a problem in Wine.

The DLL (sxs.dll) and function (CreateAssemblyCache, or a related function) in question are not available on all Windows platforms, so our installer very carefully:

  1. Checks for the presence of sxs.dll, then
  2. Checks for the availability of CreateAssemblyCache, and only then
  3. Calls that function.

What Wine does wrong is to provide the DLL and the function, but then bomb out when the function is called. What they should do instead is either not provide the function at all, or just return an error code when it's called.

Update: This problem was resolved in Wine release 1.1.20 when sxs.CreateAssemblyCache() was modified to return an error code (E_NOTIMPL) rather than causing a fatal error (fix courtesy of Kai Blin). If you experience this issue, then update your Wine installation to release 1.1.20 or later; this should resolve the problem. You can then use the normal Windows installer as documented on the Publish or Perish on GNU/Linux page.

Other software issues

What are all these data files doing in the %APPDATA%\Publish or Perish folder?

Publish or Perish stores your queries and their results in files and folders in your personal data folder on your computer. Some of these are essential, while others are merely useful. The precise location of the Publish or Perish data folder depends on the operating system:

  • Windows: %APPDATA%\Publish or Perish
  • macOS: ~/Library/Application Support/Publish or Perish

You may find the following folders and files in the PoP data area:

Cache folder
Contains the raw, cached replies from the various data sources. They can be safely deleted (the Tools > Clear Cache command does that) but will incur some cost when earlier queries are repeated and may cause Google Scholar (for example) to throw more CAPTCHAs at you.
Results6 folder
Contains the parsed results, one .json file per query. Do not delete these, or you will lose your query results.
Results3, Results5 folders
If you still have these but are now using PoP 6.x exclusively, then you can delete those folders.
Temp folder
Files in this folder may be safely deleted once PoP has exited.
Trash folder
Contains backup copies of the previous query tree, plus the results of queries that have since been deleted, just like the Windows Recycle Bin. The Trash contents are (safely) trimmed by the Tools > Clear Garbage command. You can also delete them manually, but that will make previously deleted results unrecoverable.

Further information about PoP's backup regime can be found under "On-disk backup copies" in the Preferences: General dialog box.

Help! All my folders and queries have disappeared!

Sorry to hear about this. Couple of points:

  1. You do not have to save or archive your data manually. Publish or Perish automatically saves any changes, usually within 2 seconds of the completion of your query.
  2. But: the final data saving happens only when Publish or Perish is exited normally. This is when the last bookkeeping information is committed to disk.
  3. It is therefore highly recommended to exit/quit Publish or Perish normally before switching off your computer or putting it to sleep. This includes closing the lid of a laptop computer.
  4. This also applies to virtual machines; just terminating the virtual machine is the equivalent of yanking out the power cable and can lead to data loss.

It depends on the operating system (macOS or Windows) and version (10.13-10.15, or 7/8/10) how well applications are notified of the impending operating system shutdown/sleep/termination, and if Publish or Perish is in the middle of a background save, this may cause problems and lead to data loss.

To restore your queries, do this:

  1. Exit/Quit all running instances of Publish or Perish.
  2. Go to the Publish or Perish data folder on your computer.
    • Windows: use Windows Explorer to go to C:\Users\<yourname>\AppData\Roaming\Publish or Perish folder (or just type %APPDATA%\Publish or Perish in the Windows Explorer address bar and press Enter)
    • macOS: in Finder, use the Go > Go to Folder... command to go to ~/Library/Application Support/Publish or Perish folder (normally hidden in Finder)
  3. In that folder, there should be a file called Queries6.qml. There may also be files called Queries6.cur.qml,, and Queries6.old.qml.
  4. If there are several of these files, then select the largest (by file size) and rename that to Queries6.qml. You may have to rename the existing Queries6.qml --if any-- for that.
  5. If you can only find a small (1-5 kB) Queries6.qml file, then go into the Trash subfolder to look for files called q6_xxxxxxxx.qml, where the 'xxxxxxxx' portion is some hexadecimal number.
  6. Select the largest file from these and copy it to the Publish or Perish base folder, then rename it to Queries6.qml (again, you may have to rename the existing Queries6.qml file).
  7. Finally, restart Publish or Perish. Your queries should be back.

And please remember to exit/quit Publish or Perish normally before switching off your computer or forcibly putting it to sleep. (If the computer is going to sleep due to several minutes of idle time, this is usually not a problem because Publish or Perish will have finished any background saves by then, but it's still a good idea to exit Publish or Perish first.)

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