John Adams, Abigail Adams, Thomas Jefferson (1988). “The Adams-Jefferson Letters: The Complete Correspondence Between Thomas Jefferson and Abigail and John Adams”
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.
John Adams, Charles Francis Adams (1856). “The Works of John Adams, Second President of the United States: With a Life of the Author, Notes and Illustrations”, p.235
"Christianity: the One, the Many: What Christianity Might Have Been and Could Still Become, Volume 1". Book by John F. Nash (p. 11), February 14, 2008.
James C. Humes, Benjamin Franklin (1995). “The wit and wisdom of Benjamin Franklin: a treasury of more than 900 quotations and anecdotes”, Harpercollins