1. Agrawal, A.W., Nixon, H.: What Do Americans Think About Federal Tax Options to Support Public Transit, Highways, and Local Streets and Roads? Results from Year Seven of a National Survey. Mineta Transportation Institute, San Jose (2016)
2. Agrawal, A.W., Dill, J., Nixon, H.: Green transportation taxes and fees: a survey of public preferences in California. Transp. Res. D – Transp. Environ 15, 189–196 (2010)
3. Agrawal, A.W., Nixon, H., Hooper, A.M.: Public Perceptions of Mileage-Based User Fees (NCHRP Synthesis 487). National Academy of Sciences, Washington (2016)
4. American Association for Public Opinion Research (AAPOR): AAPOR response rate calculator.
http://www.aapor.org/Education-Resources/For-Researchers/Poll-Survey-FAQ/Response-Rates-An-Overview.aspx
(2016). Accessed 31 Aug 2017
5. D’Artagnan Consulting, DHM Research, and PRR, Inc.: Final baseline public opinion research report. Prepared for the California Road Charge Technical Advisory Committee (2015)