About: http://webisa.webdatacommons.org/167969704

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	But for most of that time, signatures were a convention rather than a legal requirement.
http://www.w3.org/ns/prov#wasQuotedFrom	alta.org