Thomas Jefferson (2011). “Jefferson on Freedom: Wisdom, Advice, and Hints on Freedom, Democracy, and the American Way”, p.11, Skyhorse Publishing, Inc.
George Washington (1837). “The writings of George Washington: being his correspondence, addresses, messages, and other papers, official and private, selected and published from the original manuscripts; with a life of the author, notes, and illustrations”, p.187
United States. President (1981-1989 : Reagan), United States. President (1981-1989 : Reagan)., Ronald Reagan, United States. Office of the Federal Register (1983). “Ronald Reagan”