1. Did highways cause suburbanization?;Baum-Snow;Quarterly Journal of Economics,2007
2. Where are the Jobs?;Brennan,1999
3. Bureau of the Census, 2011. Resident Population Data Population Density. http://2010.census.gov/2010census/data/apportionment-dens-text.phpSkip (viewed 20.04.11) (top horizontal navigation section).
4. Bureau of Transportation Statistics, 2001. National Household Travel Survey 2001.
5. Bureau of Transportation Statistics, Research and Innovative Technology Administration, 2011. Key Transport Indicators.