Check that a quoted passage appears word for word in its cited source (URL, DOI or PubMed ID).
Free
One server, in research. Check that a quoted passage appears word for word in its cited source (URL, DOI or PubMed ID).
Research
Check that a quoted passage appears word for word in its cited source (URL, DOI or PubMed ID).
The rest either hold an API key issued by the publisher or ask for nothing.
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