David Ricardo, John Ramsay McCulloch (1846). “The Works of David Ricardo, Esq., M.P.: With a Notice of the Life and Writings of the Author”, p.380, London, J. Murray
David Ricardo, John Ramsay McCulloch (2000). “The Works of David Ricardo, Esq., M.P.: With a Notice of the Life and Writings of the Author”, p.372, The Lawbook Exchange, Ltd.