About: http://webisa.webdatacommons.org/240478137

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	R1, R2 and R3 independently are a hydrogen atom or a methyl radical, it being understood that R1, R2 and R3 cannot simultaneously be a methyl radical; and
http://www.w3.org/ns/prov#wasQuotedFrom	google.com.au