About: http://webisa.webdatacommons.org/313633645

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	As materials constituting the regions L and M respectively, birefringent materials other than crystal and quartz or materials other than white sheet glass having no birefringence may be used.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com