Yankee from the West: The Candid, Turbulent Life Story of the Yankee-born U. S. Senator from Montana, by Burton K. Wheeler and Paul F. Healy, Garden City, NY: Doubleday & Co., Inc., 1962, full text online
Coan, Blair (1925). The Red Web: An Underground Political History of the United States from 1918 to the Present Time. Northwest Publishing Co. LCCN26000277.