About: http://webisa.webdatacommons.org/439835514

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	I do not see any reason to use it and find it somewhat unlucky to appear in a book about Mathematica programming, especially if there is no explanation why it is there (I do not know the book, maybe there is an explanation?).
http://www.w3.org/ns/prov#wasQuotedFrom	stackexchange.com