1. Arizona Department of Environmental Quality (ADEQ), 2005. Arizona Alternative Compliance and Testing Study (AZACTS)—summary of activities and recommendations to date. 〈http://www.azdeq.gov/environ/air/vei/download/1205report.pdf〉.
2. Bishop, G.A., Williams, M.J., Burgard, D.A., Stedman, D.H., 2003a. On-road remote sensing of automobile emissions in the Chicago area: year 5, September 2002. Final Report to the Coordinating Research Council, Inc., USA, September 2003. 〈http://www.feat.biochem.du.edu/reports.html〉.
3. Bishop, G.A., Burgard, D.A., Williams, M.J., Stedman, D.H., 2003b. On-road remote sensing of automobile emissions in the phoenix area: year 4, November 2002. 〈http://www.feat.biochem.du.edu/reports.html〉.
4. Burgard, D.A., Bishop, G.A., Williams, M.J., Stedman, D.H., 2003. On-road remote sensing of automobile emissions in the Denver area: Year 4, January 2003. Report prepared for the Coordinating Research Council under contract E-23-4, University of Denver, Denver, CO, July 2003. 〈http://www.feat.biochem.du.edu/reports.html〉.
5. China Automotive Technology & Research Center (CATARC), 2003. Study of fuel economy legislation and policy in China (in Chinese). 〈http://www.efchina.org/documents/Fuel_Economy_CN.pdf〉.