1. 1 Barros, Gerald (1976). “Asking Wages, Market Wages, and the Off-farm Labour Supply by Farm Operators”. Unpublished PhD thesis, North Caroline State University at Raleigh.
2. A Theory of Social Interactions;Becker;Journal of Political Economy,1974
3. Off-farm Work by Operators of Canadian Census-farms - 1971;Bollman;Canadian Farm Economics,1973
4. 4 Bollman, Ray D. (1976). “Economics of Off-farm Work by Census-farm Operators: Theory and Preliminary Evidence”. Paper presented to the Annual Conference of the Canadian Agricultural Economics Society, July 5-7, Halifax.
5. 5 Bollman, Ray D. (1978). “Off-farm Work by Farmers: A Study with a Kinked Demand for Labour Curve”. Unpublished PhD thesis, University of Toronto.