About: http://webisa.webdatacommons.org/439527845

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	You can mark an argument as required, but it???s still up to you to write the code to see if this required argument was supplied and, if it wasn???t, to take some sort of action.
http://www.w3.org/ns/prov#wasQuotedFrom	msdn.com