Reference & DOI Integrity Checker
Paste a reference list. For each DOI found, the tool checks Crossref's registry record — title, first author and year — against your reference text, and reports any recorded retraction or correction. This reads registry evidence for you to verify; it does not certify that your reference list is correct or complete.
Reference list input
Paste your reference list
Nothing is sent while you type. When you press Check references, each reference's extracted DOI or text is sent directly from your browser to Crossref for that one lookup; Gurjas does not receive or store it. Processing is sequential (about one reference every few hundred milliseconds) to stay within Crossref's shared public rate limits. The first 50 references are checked; anything beyond that is ignored and the count is shown.
Registry check results
How to read this. A "matches" comparison means the Crossref-recorded field was found in your reference text after normalising case and punctuation — it is a text-overlap check, not proof the citation is otherwise accurate. "Not comparable" means Crossref itself did not supply that field. Absence of a recorded update is reported as exactly that, not as proof nothing was ever corrected or retracted.
Method and limitations
Method version 1.0 · reviewed 20 July 2026. DOIs are extracted from your pasted text with a pattern match and looked up directly against the Crossref REST API (api.crossref.org). References without a recognisable DOI are searched by bibliographic text instead, and the top three Crossref results are shown as candidates to verify manually — none is ever auto-selected. Title, author and year comparisons are simple text-overlap heuristics, not authoritative bibliographic verification.
Not checked: whether a citation is used appropriately in context, DataCite or mEDRA-registered DOIs (datasets, software and some preprints are frequently registered outside Crossref and may correctly show as not found here), page numbers, or whether the cited work is available on the publisher's site. A DOI absent from Crossref is not evidence the work is illegitimate — check the DOI directly at doi.org and, for non-Crossref registrars, at DataCite.
How to read this tool
Purpose: Check each pasted reference's DOI against the Crossref registry and surface recorded post-publication updates.
- Maturity
- Production
- Method version
- 1.0
- Reviewed
- Processing
- Direct requests to named third parties
Evidence basis
- Crossref REST APIlive public API
Privacy
Each reference's DOI or text goes directly from the browser to Crossref; Gurjas does not receive it.
Limitations
Comparisons are text-overlap heuristics, not authoritative bibliographic verification. A DOI absent from Crossref is not evidence a work is illegitimate; it may be registered with a different agency.
Decision boundary
Does not certify a reference list as correct or complete; it reports registry evidence for manual verification.
Use the result. Check the reasoning.
This interface is a decision aid—not an automatic verdict. The 2 linked Library entries explain the source workflow, assumptions and boundary conditions that should travel with the result.