1. EPA-Gasoline RIA, Regulatory Impact Analysis—Control of Air Pollution from New Motor Vehicles: Tier 2 Motor Vehicle Emissions Standards and Gasoline Sulfur Control Requirements, US Environmental Protection Agency, Air and Radiation, EPA420-R-99-023, December 1999.
2. EPA-RFG-II, Phase II RFG Report on Performance Testing, US Environmental Protection Agency, Air and Radiation, EPA420-R-99-025, April 1999.
3. EPA, Control of Air Pollution from New Motor Vehicles Amendment to the Tier-2/Gasoline Sulfur Regulations, US Environmental Protection Agency, April 13, 2001. http://www.epa.gov/fedrgstr/EPA-AIR/2001/April/Day-13/a8927.htm.
4. EPA-Diesel RIA, Regulatory Impact Analysis: Heavy-duty Engine and Vehicle Standards and Highway Diesel Fuel Sulfur Control Requirements, United States Environmental Protection Agency, Air and Radiation, EPA420-R-00-026, December 2000.
5. EPA, EPA Gives the Green Light on Diesel Sulfur Rule, Press Release, United States Environmental Protection Agency, February 28, 2001.