United States. President (1929-1933 : Hoover), Herbert Hoover (1974). “Herbert Hoover: Containing the Public Messages, Speeches, and Statements of the President”
Herbert Hoover (1930). “Address of President Hoover at the Annual Dinner of the Chamber of Commerce of the United States: Washington, D. C., Thursday, May 1, 1930, at 9:30”
United States. President (1929-1933 : Hoover), Herbert Hoover (1974). “Herbert Hoover: Containing the Public Messages, Speeches, and Statements of the President”