1. Food 2000: Global Policies for Sustainable Agriculture A report to the World Commission on Environment and Development,1987
2. The Albrecht Papers”;Albrecht,1975
3. Soil Organic Matter and its Role in Crop Production;Allison,1973
4. In “The Importance of Biological Agriculture in a World of Diminishing Resources”;Altieri,1986
5. Agroecology: The Scientific Basis of Alternative Agriculture,”;Altieri,1987