1. Carvajal, R. (1983). The impact of a social systems scientist on a country.Omega 11, No. 6.
2. Carvajal, R., and Lomnitz, L. (1981). El Desarrollo Cient�fico de M�xico: �Es posible multiplicarlo con los mismos recursos?Ciencia y Desarrollo 7, No. 37.
3. Checkland, P. B. (1971). A systems map of the universe.J. Syst. Eng. 2, No. 2.
4. Churchman, C. W. (1968).The Systems Approach, Dell, New York.
5. Churchman, C. W. (1971).The Design of Inquiring Systems, Basic Books, New York.