Forrest, Earle R. (1936). Arizona's Dark and Bloody Ground; an authentic account of the sanguinary Pleasant Valley vendetta that swept through Arizona's cattleland in the latter eighteen eighties – the Graham-Tewksbury feud. Caldwell, Idaho: Caxton Printers, Ltd. pp. 15, 292. OCLC1825248.
Burnham, Frederick Russell (1926). Scouting on Two Continents. Doubleday, Page & company. pp. 2, Chapters 3 & 4. OCLC407686.