1. 1ACC/SCN. 1993. Second Report on the World Nutritional Situation. FAO. Rome.
2. 2Allen, T.F.H. & T.B. Starr. 1982. Hierarchy. The University of Chicago Press. Chicago.
3. 3Brooks, D.R. & E. O. Wiley. 1988. Evolution as Entropy. University of Chicago Press. Chicago.
4. Entropy and information in evolving biological systems
5. 5Chesnais, J.C. 1992. The Demographic Transition. Clarendon Press. New York.