America Quotes - Page 180
Henry David Thoreau (2012). “The Portable Thoreau”, p.137, Penguin
Harry S. Truman (1960). “Truman Speaks”, New York : Columbia University Press
Harry S. Truman (1967). “The Quotable Harry S. Truman”, Anderson, S.C. : Droke House, distributed by Grosset & Dunlap
United States. President (1945-1953 : Truman), Harry S. Truman (1966). “Harry S. Truman: Containing the Public Messages, Speeches, and Statements of the President, 1945-53”
Harriet Beecher Stowe (1854). “Sunny Memories of Foreign Lands (Complete)”, p.174, Library of Alexandria
"Managing". Book by Harold Geneen, p. 86, 1984.