About: http://webisa.webdatacommons.org/193205103

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	he is seems like a problem: with quotes around null, it means then position property is a string.
http://www.w3.org/ns/prov#wasQuotedFrom	stackoverflow.com