5Buchanan, James M. Social Choice, Democracy, and Free Markets. Journal of Polticial Economy, 1960.
6Plant,Jeremy F. (2001). "Codes of Ethics."in Cooper, Terry Led., Handbook of Administrative Ethics.New York: Marcel Dekker.
7Bowman,James S.,Jonathan P.West,Evan M.Berman, Montgomery Van Wart (2004). The Professional Edge: Competencies in Public Service.New York=M.E.Sharpe,lnc.