1. Firm Enterprise Data System
2. National Academy of Sciences, Panel on Nitrates and the Coordinating Committee for Scientific and Technical Assessment of Environmental Pollutants: 241 (1978).
3. Report and Recommendations on Organic Farming 1980
4. Soil and Water Resources Conservation Act: Appraisal 1980 Review Draft Part I 1980
5. 1974 Census of Agriculture 1977