Peter L. Bernstein (2012). “Peter L. Bernstein Classics Collection: Capital Ideas, Against the Gods, The Power of Gold and Capital Ideas Evolving”, p.321, John Wiley & Sons
John Rae (1834). “Statement of Some New Principles on the Subject of Political Economy: Exposing the Fallacies of the System of Free Trade, and of Some Other Doctrines Maintained in the "Wealth of Nations."”, p.123