7Geoff Whitty , Sally Power and David Halpin , Devolution and choice in education : the school , the state , and the market.Open University Press.1998.(115-122)
8Milton Friedman ,Public Schools: Make Them Private.Washington Post. 1995.
9Edwin G West, ″Education Vouchers in Practice and Principle: A World Survey″.
10King E,Rawlings L, Gutierrez M,Pardo,C&Torres C. Columbia″s Targeted Education Voucher Program:Features,Coverage and Participation, The World Bank.1997.3.