Check every reference in a thesis before you submit it

A reference list can look right and still be wrong. A reference checker has to answer three questions about each entry: does the work exist, are its authors and year right, and does the sentence citing it say what the work says. A citation-style checker only answers a fourth, whether the commas are in the right places.

hedwigai answers the three. Give it the whole draft, from Word, Google Docs, LaTeX or a PDF turned into text. It looks up every entry under References or Bibliography in Crossref and on the web, then reads each sentence that cites one, whether as [3], (Smith et al., 2020) or a footnote, against the work found. Your words come back exactly as written, with a verdict and its source beside each.

More theses, literature reviews and grant proposals are now drafted with an AI, and AI writing tools produce references that look exactly like real ones. Walters and Wilder checked all 636 works cited in 84 papers ChatGPT wrote. More than half of GPT-3.5’s references did not exist. GPT-4 did better, but still invented almost one in five, and a quarter of its real references had the wrong year, authors or pages.

Newer models invent fewer, but none invents none. And a sentence can cite a real paper that says something else. Your examiner checks by hand, so check first.

It tries the DOI first, when the entry gives one. Then it searches Crossref for the title and reads every record with that title, not just the top hit, because titles get reused. When we built it, the top Crossref hit for “Language models are few-shot learners” was a 2026 record with the same title, not the 2020 paper. Only when Crossref has nothing does it search scholarly sites on the web for the exact title.

It never calls a reference fake. Books, theses, reports and very new or non-English work are often missing from Crossref, so “not found” means look it up yourself, not delete it.

Each sentence that cites a reference gets its own verdict: cited when the work states it, contradicted when a source says otherwise, with the passage quoted, and no source when nothing read states it. A sentence whose reference wasn’t found says so.

Three sentences and three references: one correct, one with the wrong year, and one we made up for the test. The check took 53 seconds.

In Claude, connect hedwigai from the connector directory, attach your draft and ask it to check the references. In Claude Code, Codex, Cursor or any agent that reads skills, add the reference-checker skill, which tells the agent how to turn your file into markdown, start the check and report what it found:

npx skills add un-seen/hedwigai-skills --skill reference-checker

A check is billed per reference. A thesis with 80 references costs a few dollars, and your first workbook is covered by sign-up credit.