About: http://webisa.webdatacommons.org/435315954

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	Additionally, one of the effects most studied is the negative index of refraction.[1][3][6][7]
http://www.w3.org/ns/prov#wasQuotedFrom	wikipedia.org