Samuel Johnson (1798). “Dr. Johnson's Table Talk: Containing Aphorisms on Literature, Life, and Manners; with Anecdotes of Distinguished Persons, Selected and Arranged from Dr. Boswell's Life of Johnson”, p.126
Mark Twain (2014). “Mark Twain on Common Sense: Timeless Advice and Words of Wisdom from America's Most-Revered Humorist”, p.37, Skyhorse Publishing, Inc.