Price G. Price Tags 101. March 11, 2008; Pucher J., Buehler R., Seinen M. Bicycling Renaissance in North America? An Update and Re-Appraisal of Cycling Trends & Policies. Transportation Research Part A: Policy and Practice. 2011. Vol. 45. No. 6. Pp. 451–475; Nussbaum P. More bicyclists means fewer accidents, Phila. finds // Philly.com. Philadelphia Inquirer and Philadelphia Daily News. 2012. September 17 // .
