Diary entry. "Diary and Letters of Rutherford Birchard Hayes: Nineteenth President of the United States". Book edited by Charles Richard Williams, The Ohio State Archaeological and Historical Society, February 14, 1879.
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