1. National Research Council. Guidelines for Developing Community Emergency Exposure Levels for Hazardous Substances. Washington DC:National Academy Press 1993.
2. Superfund Amendments and Reauthorization Act Title Ill. U.S. Congress 1986.
3. Clean Air Act Amendments Section 112(r). U.S. Congress 1990.
4. Global Population and the Nitrogen Cycle
5. Lonsdale H. Ammonia tank failure-South Africa. Am