1. Nielson E.G. , and Lee L.K. The Magnitude and Costs of Groundwater Contamination from Agricultural Chemicals: A National Perspective. USDA Agricultural Economic Report No. 576, 1987.
2. Low-Input Agriculture: Trends, Goals, and Prospects for Input Use;Daberkow;American Journal of Agricultural Economics,1989
3. U.S. General Accounting Office. Sustainable Agriculture Program Management, Accomplishments and Opportunities. GAO/RCED-92-233, 1992.
4. Toward a More General Theory of Regulation