Theodore Roosevelt (2015). “Theodore Roosevelt on Bravery: Lessons from the Most Courageous Leader of the Twentieth Century”, p.13, Skyhorse Publishing, Inc.
United States. Congress. Joint Economic Committee, Hyman George Rickover (1982). “Economics of Defense Policy: Adm. H.G. Rickover : Hearing Before the Joint Economic Committee, Congress of the United States, Ninety-seventh Congress, Second Session”