About: http://webisa.webdatacommons.org/388006721

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	Numerous studies, based on a variety of techniques such as ultracentrifugation and electron microscopy indicated a particulate nature for asphaltenes with size 20-40 A diameter.
http://www.w3.org/ns/prov#wasQuotedFrom	worldwidescience.org