About: http://webisa.webdatacommons.org/207030126

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	Your validation rules are not strict enough, unless you care only about there being 3 periods present. ..., a.b.c.d are just two simple examples of things that are clearly, completely invalid, but your code allows.
http://www.w3.org/ns/prov#wasQuotedFrom	stackexchange.com