The following publication contains information about William Capes:
Article: "Greasy Grass: Looking Back" by Ron Nichols • In its 25 years of publication, Greasy Grass has covered many topics about the Little Bighorn battle and its personalities. Ron Nichols takes us on a walk down memory lane of Greasy Grass. • Greasy Grass, Journal of the Custer Battlefield Historical & Museum Association, Vol. 25, May 2009.