1. Bailey, William B. and Julius H. Parmelee (1910), ‘The age returns of the twentieth census’, Publications of the American Statistical Association, 12, pp. 110–23.
2. Blitch, Charles P. (1995), Allyn Young: The Peripatetic Economist, Basingstoke and London: Macmillan Press Ltd.
3. Ely, Richard T., Thomas S. Adams, Max O. Lorenz and Allyn A. Young (1923), Outlines of Economics, New York: The Macmillan Company.
4. Friedman, Milton (1965), ‘Transfer Payments and the Social Security System’, National Industrial Conference Board Record 2 (September), pp. 7–10.
5. Keynes, John M. (1919; 1920), The Economic Consequences of the Peace, New York: Harcourt, Brace and Howe.