Will Rogers, Bryan B. Sterling, Frances N. Sterling (1993). “Will Rogers' World: America's Foremost Political Humorist Comments on the Twenties and Thirties--and Eighties and Nineties”, p.92, Rowman & Littlefield
"A Dictionary of Thoughts : Being a Cyclopedia of Laconic Quotations from the Best Authors, Both Ancient and Modern" edited by Tryon Edwards, (p. 324), 1891.