1. National Air Pollutant Emission Trends, 1900-94; U.S. Environmental Protection Agency. Office of Air Quality Planning and Standards: Research Triangle Park, NC, 1995; EPA 454/R–95–001 .
2. Electric Utility Phase I Acid Rain Compliance Strategies for the Clean Air Act Amendments of 1990; U.S. Department of Energy. Energy Information Administration: Washington, DC, 1994; DOE/EIA–0582 .
3. Acid Rain Program Emissions Scorecard 1994; U.S. Environmental Protection Agency. Acid Rain Division (6204J): Washington, DC, 1995; EPA 430/R–95–012 .
4. Calculated by authors, based on Acid Rain Program Emissions Scorecard 1995; U.S. Environmental Protection Agency, 1996. http://www.epa.gov/acidrain/scorcard/es1995.html. Appendix A; Emissions Data; U.S. Environmental Protection Agency. http://www.epa.gov/acidrain/etsdata.html. Acid Rain Program. February 1996 .
5. Calculated, based on References 12 and 26 .