Nearing and Watson: Economics, pages 241-255, 314-320.
Vrooman: American Railway Problems, pages 1-181.
Bolen: Plain Facts as to the Trusts and the Tariff, pages 3-236.
Bogart: Economic History of the United States, pages 186-216, 305-337, 400-418.
Montgomery: Vital American Problems, pages 3-91.