About: http://webisa.webdatacommons.org/143939555

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	If we want to get the value of an optional element or attribute, and we know that the value is an integer or double, or whatever, instead of casting to string, we can cast to any of the other nullable types.
http://www.w3.org/ns/prov#wasQuotedFrom	msdn.com