<http://webisa.webdatacommons.org/prov/490604305>	<http://www.w3.org/ns/prov#wasDerivedFrom>	<http://webisa.webdatacommons.org/123266189> .
<http://webisa.webdatacommons.org/123266189>	<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>	<http://www.w3.org/ns/prov#Entity> .
<http://webisa.webdatacommons.org/123266189>	<http://www.w3.org/ns/prov#wasQuotedFrom>	<ietf.org> .
<http://webisa.webdatacommons.org/123266189>	<http://www.w3.org/ns/prov#value>	" systems, there is a need to define Uniform Resource Identifiers" .