1. AGA/NGVC. 1991. Natural gas vehicle fleet market study. The American Gas Association and the Natural Gas Vehicle Coalition (prepared by Easton Consultants)
2. Allen, R.W., Madison, D.L., Porter, L.W., Renwick, P.A., Mayes, B.T., 1979. Organizational politics: tactics and characteristics of its actors. California Management Review 22, pp. 77–83
3. Essence of Decision;Allison,1971
4. Berg, M., 1984. Electric vehicles in commercial sector applications: a study of market potential and vehicle requirements. Prepared for the Electric Power Research Institute, Institute for Social Research, University of Michigan
5. The potential market for electric vehicles: results from a national survey of commercial fleet operators;Berg;Transportation Research Record,1985