1. US EPA.: National emissions inventory (NEI) air pollutant emissions trends data (1970–2012). http://www.epa.gov/ttn/chief/trends/index.html (2012). Accessed July 2012
2. US EPA .: Greenhouse gas emissions from the US transportation sector, 1990–2003. Transportation GHG emissions report (2006)
3. Kahn, M.E.: New evidence on trends in vehicle emissions. The RAND J. Econ. 27(1), 183–196 (1996)
4. Yin, Y., Lawphongpanich, S.: Internalizing emission externality on road networks. Transp. Res. Part D Transp. Environ. 11(4), 292–301 (2006)
5. Callan, S., Thomas, J.: Environmental Economics and Management: Theory, Policy, and Application. Fort Worth: The Dryden Press (1996)