I like WikiData for tasks like these that require consolidating multiple different identifiers for the same work. E.g. https://www.wikidata.org/wiki/Q106545884

I like WikiData for tasks like these that require consolidating multiple different identifiers for the same work. E.g. https://www.wikidata.org/wiki/Q106545884 https://www.wikidata.org/wiki/Q106545884 Gives us the ISBN, Goodreads work id, LibraryThing id, the OpenLibrary id, and the Google Knowledge Graph id all in one query.