Benjamin Franklin, William-Temple Franklin (1818). “Memoirs of the Life and Writings of (the Same), Continued to the Time of His Death by William Temple Franklin. - London, H. Colburn 1818”, p.270
John D. Rockefeller (2015). “John D. Rockefeller on Making Money: Advice and Words of Wisdom on Building and Sharing Wealth”, p.32, Skyhorse Publishing, Inc.