About: http://webisa.webdatacommons.org/72213479

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	Though the flicker frequency depends upon many factors, such as brightness and color of stimulus, a value of at least 30 Hz is preferred for practice purposes.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com