E. A.  Machado, Stoms, D. M., Davis, F. W., and Kreitler, J., ?Prioritizing farmland preservation cost-effectively for multiple objectives?, Journal of Soil and Water Conservation, vol. 61, pp. 250-258, 2006.

E. A.  Machado, Stoms, D. M., and Davis, F. W., ?A systematic framework for prioritizing farmland preservation?, National Center for Ecological Analysis and Synthesis, Santa Barbara, 2003.