BBC: William II (c.1056 - 1100) - Biography of the king called William Rufus because of his ruddy complexion, he was the second son of William the Conqueror. - http://www.bbc.co.uk/history/historic_figures/william_ii_king.shtml
The Normans: William II - Outline of the reign of William II (William Rufus). - http://www.royal.gov.uk/output/Page53.asp
William II - Short biography of the King of England (1087–1100), called William Rufus or William the Red. - http://www.factmonster.com/ce6/people/A0852296.html