How to check if a citation is real
A citation can be wrong in small ways (a typo in the year, a DOI that points elsewhere) or not exist at all, which happens more often now that AI writing tools produce plausible-looking references. Here is how to check one by hand, what the warning signs are, and how to check a whole reference list at once.
Why citations go wrong
Most broken references are honest mistakes: a reference manager filled in the wrong metadata, a preprint was later published under a different title or year, or a DOI was copied from a neighbouring entry. These are easy to fix once you see them.
A newer problem is references that never existed. Large language models generate text that looks like a citation (real-sounding authors, a plausible journal, a correct-looking DOI format) without checking that the work is real. Reviewers and editors increasingly look for this, and a single invented reference can undermine trust in the whole paper.
Check a single reference in five steps
- Resolve the DOI. If the reference has a DOI, open https://doi.org/ followed by the DOI. A DOI that resolves nowhere is a red flag. A DOI that opens a different paper means it was copied wrongly.
- Match the title. Compare the title on the publisher page with the one in your reference. Small differences (punctuation, a subtitle) are common; a different topic is not.
- Match the year and first author. Preprints and journal versions often differ by a year. Decide which version you cite and make the year, venue and DOI all refer to that same version.
- Search the title if there is no DOI. Search the exact title in quotation marks in Crossref, OpenAlex, Google Scholar or arXiv. A real paper almost always appears in at least one of them.
- Confirm the claim you cite. Existence is not enough: open the paper and check that it says what you cite it for. This is the step automated tools cannot do for you.
Warning signs of an invented citation
- The DOI has the right format but does not resolve, or resolves to an unrelated paper.
- The title cannot be found in any bibliographic database, even with small variations.
- Well-known authors appear on a paper that is not listed on their own publication pages.
- The journal exists but the volume, issue or page range does not match anything it published.
- Several references share an unusual pattern, such as identical page ranges or very generic titles.
Check a whole reference list at once
Checking fifty references by hand takes hours. Bibliographic databases make it possible to automate the first four steps: resolve each DOI or arXiv ID, search the remaining titles, and compare title, year and first author with the record that comes back.
Whatever tool you use, treat the result as a list of entries to look at, not a verdict. Books, software, datasets and web pages are less consistently indexed, so a "not found" for those usually means "check by hand" rather than "invented".
Keep references clean while you write
- Import references from the publisher or a database (Crossref, PubMed, arXiv) rather than typing them.
- Prefer the published version over the preprint once it exists, and update year, venue and DOI together.
- Never paste a reference produced by an AI assistant without checking that the work exists.
- Run a full check before submission and again after the last round of edits.
Questions
How can I tell if a citation was made up by ChatGPT?
Look it up: resolve its DOI and search its exact title in Crossref, OpenAlex or Google Scholar. An invented citation usually has a DOI that does not resolve or points to a different paper, and a title that appears in no database.
Does a DOI prove a reference is correct?
No. A DOI proves that some work exists. Check that it opens the same title, authors and year you cite; copied DOIs that point to a different paper are a common error.
Is a reference that is not in Crossref fake?
Not necessarily. Books, theses, software and web pages are often missing from Crossref. Check those by hand before concluding anything.