Benjamin Franklin (1987). “Poor Richard's Almanack: Being the Choicest Morsels of Wisdom, Written During the Years of the Almanack's Publication”, p.16, Peter Pauper Press, Inc.
James C. Humes, Benjamin Franklin (1995). “The wit and wisdom of Benjamin Franklin: a treasury of more than 900 quotations and anecdotes”, Harpercollins
Thomas Jefferson (1854). “The Writings of Thomas Jefferson: Inaugural addresses and messages. Replies to public addresses. Indian addresses. Miscellaneous: 1. Notes on Virginia; 2. Biographical sketches of distinguished men; 3. The batture of New Orleans”, p.400
Mark Twain (2014). “Mark Twain on Common Sense: Timeless Advice and Words of Wisdom from America's Most-Revered Humorist”, p.31, Skyhorse Publishing, Inc.