1. American Public Transportation Association: Public transportation takes us there. http://www.publictransportation.org/benefits/Pages/default.aspx (2012a). Accessed 8 July 2012
2. American Public Transportation Association: 2012 Public Transportation Fact Book Appendix A: Historical Tables. American Public Transportation Association, Washington D.C. (2012a)
3. American Public Transportation Association: 2012 Public Transportation Fact Book. American Public Transportation Association, Washington D.C. (2012b)
4. Baldwin, J.N.: Public versus private: not that different, not that consequential. Public Pers. Manag. 16(2), 181–193 (1987)
5. Barton, A.H.: A diagnosis of bureaucratic maladies. In: Weiss, C.H., Barton, A.H. (eds.) Making Bureaucracies Work, pp. 27–36. Sage, Beverly Hills (1980)