Tomorrowish · How to check a citation · Journal and university rules
Bibliography Verifier for Google Docs
A sidebar for Google Docs that looks up every entry in your reference list in the open scholarly indexes, tells you which ones it found, which have wrong details, which were retracted and which it could not find, and fixes the details you choose.
Status: built and tested, not yet in the Google Workspace Marketplace (it has to pass Google's review first). Free. This page will link to the listing when it is live.
What it checks
- The DOI, resolved through Crossref, DataCite and the DOI registry, and compared with the title the reference gives.
- Title, authors, year, journal, volume and first page, matched against Crossref, PubMed, arXiv and OpenAlex. Before it calls anything a mismatch it asks a second index, because the same title often exists as a preprint, a conference paper and a journal article.
- Books in Open Library and the Library of Congress catalogue.
- Retractions, from the Retraction Watch data that Crossref publishes, and PubMed's retraction flags.
- Web links: whether the page opens and carries the cited title, and whether the Internet Archive has a copy.
It reads APA, MLA, Chicago, Harvard, IEEE and Vancouver styles, from the list under a heading called References, Bibliography or Works Cited, or from paragraphs you select.
What each result means
Verified
A record matches the title and authors. The add-on can add the DOI link if the reference lacks one.
Mismatch
The work exists, but the reference gets something wrong: a year, an author, the journal, the volume or pages, or a DOI that belongs to another paper. The real record is shown next to it.
Retracted
The work exists and has a retraction notice, linked so you can read it.
Not found
No open index has it. This is a prompt to check by hand, not a finding that it was made up: books, theses, reports, older and non-English work are often missing.
What it changes in your document
Only what you click. Each fix shows the old and new text first (for example 1949 → 1948), keeps the reference's style and formatting, and is an ordinary edit you can undo with Ctrl+Z or version history. You can also add a dated check log or a one-line note for an instructor or editor. It never writes or suggests new references.
How accurate it is (measured, not promised)
Two test sets, run on 24 October 2026. Both sets, the expected answers and the scripts are kept with the add-on's source.
| Test | Bibliography Verifier | RefRunner (free web checker, guest) |
|---|---|---|
| 20 references written for this test: 10 correct, 1 retracted, 5 with a planted error (wrong year, co-author, journal), 3 invented, 2 books | 20 of 20 right; caught 9 of 9 problems; 0 false alarms | 18 of 20 right; caught 8 of 9; 1 false alarm (an arXiv DOI) |
| 72 real references from five published PLOS ONE articles, rewritten into six styles | Flagged 11: 8 were real errors in the published lists (misspelt author names, wrong pages, a wrong co-author); 3 were false alarms (an index record with swapped names, two book chapters missing from the indexes) | Not run (guest limit is 20 a day) |
| 15 of those real references with one planted error, and 10 invented references | Caught 13 of the 13 planted errors that were visible (2 were hidden behind "et al.") and all 10 invented ones | Not run |
The 20-entry set was written by the people who built the checker, so its perfect score is the friendlier of the two numbers; the PLOS set is the fairer test. Results depend on the indexes answering: when one doesn't, the add-on says "Not checked" rather than guessing.
Price
Free, up to 50 references per document per day. A Pro plan (unlimited checks, applying all fixes at once, a printable log) is planned at $4 a month or $19 a year, with a 14-day refund. Nothing is for sale yet.
Privacy
The add-on can only open the document it runs in. Reference entries are sent to our lookup server to be looked up and are not stored. No account, no ads. Full privacy policy.