About: http://webisa.webdatacommons.org/15868287

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	1539 ??? Christopher Clavius, German mathematician was a German Jesuit mathematician and astronomer who was the main architect of the modern Gregorian calendar. (d. 1612)
http://www.w3.org/ns/prov#wasQuotedFrom	unerasedhistory.com