Alan Greenspan's Testimony Before the Committee on Banking and Financial Services, U.S. House of Representatives, www.federalreserve.gov. July 24, 1998.
David Ricardo, John Ramsay McCulloch (1852). “The Works of David Ricardo. With a notice of the life and writings of the author: by J. R. McCulloch”, p.7
John Maynard Keynes (1929). “The Economic Consequences of the Peace: The classic text on the Treaty of Versailles and post war Europe”, p.141, Harriman House Limited