The xISBN web service supplies ISBNs and other information associated with an individual intellectual work that is represented in WorldCat. Submit an ISBN to this service, and it returns a list of related ISBNs and selected metadata.
Ideal for web-enabled search applications—such as library catalogs and online booksellers—and based on associations made in the WorldCat database, xISBN enables an end user to link to information about other versions of a source work.
Datos.bne.es is the Linked Data service of the National Library of Spain. It is
a joint experimental development by the BNE and the Ontology Engineering Group (a leading pioneering group in Semantic Web in Spain, from the Technical University of Madrid), whose aim is to explore capabilities of an alternative enhanced view of its bibliographic and authority records, based in FRBR as a reference model and Linked Open Data as a web-friendly publishing and exposure frame.
"What is a Work?" is an oft-discussed question. Answers tend to come down on one side or another of what is essentially a philosophical reaction to the inherent abstractness of the nature of the FRBR Work.