Reference Checker (Purplelink)

Paste a BibTeX file or a reference list and get back, for each entry, whether a matching published paper was found in Crossref or Semantic Scholar. Entries with no match, or only a weak title match, are marked likely hallucinated, so invented citations stand out. You also see mismatches in year, authors and venue, the matched DOI and title, and whether Crossref records the paper as retracted, corrected, or under an expression of concern, with a link to the notice. A second tool checks DOIs for retractions only. A third turns DOIs into BibTeX entries. Limits: up to 100 references or 50 to 100 DOIs per call. A match means a paper with that title exists, not that it supports the claim it is cited for. A clear retraction result is not a guarantee: very recent retractions may not be in Crossref yet. Books, theses and web pages are often absent from Crossref, so "not found" means check by hand. References you send go to Crossref and Semantic Scholar; Purplelink stores nothing. For researchers, students and editors who need to check a bibliography before submitting.