About: http://webisa.webdatacommons.org/17633547

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	For all reference types this is null, and for the value types see the link that @Blorgbeard posted (or write some code to check it).
http://www.w3.org/ns/prov#wasQuotedFrom	stackoverflow.com