1. Alcorn, J. B. (1984).Huastec Mayan Agriculture. University of Texas Press, Auslin.
2. Altieri, M. A., and Trujillo, J. (1987). The agroecology of corn production in Tlaxcala, Mexico.Human Ecology 15(2): 189?220.
3. Andrade, A., and Blanc, N. (1987). SAM's cost and impact on production. In Austin, J. E., and Esteva, G. (eds.),Food Policy in Mexico: The Search for Self-Sufficiency. Cornell University Press, Ithaca, pp. 215?248.
4. Austin, J. E., and Esteva, G. (eds.). (1987).Food Policy in Mexico: The Search for Self-Sufficiency. Cornell University Press, Ithaca.
5. Bailey, J. L., and Roberts, D. H. (1983). Mexican agricultural policy.Current History 82: 420?437.