1. The Eighth Day: Social Evolution as the Self-Organization of Energy;Adams,1988
2. Agroecology: the Scientific Basis for Alternative Agriculture;Altieri,1987
3. Expanding the definition of sustainable agriculture;Allen;American Journal Sustainable Agriculture,1991
4. Social Entropy Theory;Bailey,1990
5. An Overview of Environmental Indicators: State of the Art and Perspectives UNEP/EATR.94-0 1; RIVM/40200 1001 Environmental Assessment Sub-Program;Bakkes,1994