1. National Air Data Branch, National Air Pollutant Emissions Estimates 1940?1988, March 1990, EPA-450/4-90-001.
2. Section 110(a) of the Clean Air Act as amended August 1977.
3. Conversation with Lois Platte, Office of Mobile Sources, Environmental Protection Agency, Ann Arbor, MI.
4. USEPA, SIPs: Approval of 1982 Ozone and Carbon Monoxide Plan Revisions for Areas Needing an Attainment Date Extension; and Approved Ozone Modeling Techniques, January 22, 1981, 46 FR 7182.
5. USEPA, Compliance With the Statutory Provisions of Part D of the Clean Air Act, November 2, 1983, 48 FR 50686.