1. Abel, M. E., and Rojko, A. S. (1967). World food situation: Prospects for world grain production, consumption and trade.Foreign Agricultural Economic Report No. 35, U.S. Department of Agriculture, Washington, D.C.
2. Blakeslee, L., Heady, E. O., and Framingham, C. F. (1973).World Food Production, Demand and Trade. Iowa State University Press, Ames, Iowa.
3. Bogue, D. J. (1967). The prospects for world population control. InAlternatives for Balancing World Food Production and Needs, Center for Agricultural and Economic Development, Iowa State University, Iowa State University Press, Ames, Iowa.
4. Boyarsky, A. Y. (1967). A contribution to the problem of the world population in the year 2000. InProceedings of the World Population Conference, Belgrade 1965, United Nations, Department of Economic and Social Affairs, New York.
5. Brittain, R. (1952).Let There Be Bread. Simon and Schuster, New York.