Theodore Roosevelt, Eugene Thwing (1919). “Newer Roosevelt messages: speeches, letters and magazine articles dealing with the war, before and after, and other vital topics”
Theodore Roosevelt, H. W. Brands (2001). “African Game Trails: An Account of the African Wanderings of an American Hunter-naturalist”, p.21, Rowman & Littlefield
Address at the Sorbonne, Paris, 23 Apr. 1910. Richard M. Nixon quoted this passage in his address to the nation announcing his decision to resign the presidency, 8 Aug. 1974. See Theodore Roosevelt 1; Theodore Roosevelt 2; Theodore Roosevelt 5