1. Perlman , Selig and Taft , Philip . 1935.History of Labor in the United States, 1896–1932vol. 4, 143New York
2. Brody , David . 1960.Steelworkers in America: the Nonunion Era133–134. 161–162. Cambridge, Mass.
3. Adams , Graham Jr. 1966.Age of Industrial Violence, 1910–1915189–192. New York
4. Hessen , Robert . 1969. “A Biography of Charles M. Schwab, Steel Industrialist”. Department of History, Columbia University. unpublished doctoral dissertation