1. Effect of agricultural mechanisation on crop output: A study of the operationwise effects for HYV wheat in the Punjab;B Agarwal;Indian Economic Review,1980
2. Tractorisation, productivity and employment: A reassessment;B Agarwal;Journal of Development Studies,1980
3. Reflex�es sobre a organiza��o do mercado de trabalho agr�cola;B M B Aguirre;Revista de Economia Pol�tica,1989
4. Relationships among labor, bullock, and tractor inputs in Pakistan agriculture;F Ali;American Journal of Agricultural Economics,1992
5. Social rates of return and other aspects of agricultural research: the case of cotton research in sao paulo, brazil;H W Ayer;American Journal of Agricultural Economics,1972