I am writing a paper on Overleaf and synced my bib-file with a Zotero private group to keep my references automatically updated (explained here).

While this generally works, only about 20 out of my 30 references show up in my synced bib-document in Overleaf. Why is it that some references are excluded? I tried to find commonalities between the references not showing up, but without success so far. Thank you for any ideas.

Note: I do not have access to Overleaf Premium which has a Zotero plug-in, hence this solution.

2 Answers 2


The first thing to check is that the .bib file is actually missing the items. This might just be a problem with how you are trying to find or cite them.

If you are trying to cite some items that you think should be in the .bib file and are not finding them that way, this could be due to a syntax problem with the .bib. All the items might be there, but either the Overleaf reference search, or bibtex/biblatex itself might fail to find them if there are problems with the bib exported from Zotero. So, in Overleaf, download the .bib and check to see if the items are missing or just failing to be found. If all the entries are there and you cannot load them, you need to check the .bib file for errors.

If some bib items are actually missing, the next thing to look at is the URL that you are using from Zotero. The Zotero API uses pagination to send only a chunk of the total group library. You can either set the pagination to return more items, or use two separate URLs to bring over multiple chunks as separate bib files.

For example, https://api.zotero.org/groups/<GROUP_NUMBER>/items?format=bibtex&limit=100 should bring in in references 0 to 99 for your group.

You can find out more information on the Zotero dev forum if you search there for "group API."

  • Thank you! I checked as you recommended, and the items are actually missing. I wonder whether it actually has to do with pagination due to the relatively small number of references (<30). In any case, would this be the correct link given that I also need to include a project key? api.zotero.org/groups/<GROUP_NUMBER>/items/…> My original link was: api.zotero.org/groups/<GROUP_NUMBER>/items/…> Commented May 29, 2023 at 10:43
  • I tried the new link out, simply adding <limit=100> and it worked - thanks a lot! Commented May 29, 2023 at 10:59

As an alternative to the (correct) answer by Dan MacKinnon that will work for group libraries with more than 100 items (and has some other advantages like guaranteed stable citekeys, and more advanced bibtex support in general) you can use the Better BibTeX add-on from Zotero to set up auto-export of a group (or a collection in a group) to a .bib file that you then sync automatically, e.g. using Dropbox, GitHub or some other sync functionality. You can then point Overleaf at the URL of that file (e.g., the Dropbox share link).

  • Thank you! I will try this out next time I have a bigger project with more sources. Commented May 29, 2023 at 10:59
  • Hi, for some reason the solution above suddenly stopped working. I thus tried to implement the Better BibTex solution. However, when I import the exported bibtex file from my Google Drive via the External URL option, I get a file in html code that does not look like the original bibtex file. It looks like this <!DOCTYPE html><html><head><meta name="google" content="notranslate"><meta http-equiv="X-UA-Compatible" content="IE=edge;"><style nonce="UAYTbHA8dmyieeesaVx2ng">@font-face{font-family:'Roboto';font-style:italic;font-weight:400;src:ur....Any idea how I can solve this? Commented May 29, 2023 at 19:32
  • ChatGPT helped: The automatic link obtained from Google Drive must be edited from drive.google.com/file/d/XXXXXXXXXXXXXXXXXXXXXXXX/… to look like <drive.google.com/uc?id=XXXXXXXXXXXXXXXXXXXXXXXX> Commented May 29, 2023 at 20:06

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