Mark Twain (2014). “Mark Twain on Common Sense: Timeless Advice and Words of Wisdom from America's Most-Revered Humorist”, p.53, Skyhorse Publishing, Inc.
"Incredible Quotations: 230 Thought-Provoking Quotes with Prompts to Spark Students' Writing, Thinking, and Discussion". Book by Jacqueline Sweeney, 1997.