3W. Arthur. Lewis., 1954: Economic Development with Unlimited Supplies of Labor., Manchester Sch. Econ. Soc. Stud., Vol.22, pp.139~191.
4Fei.J.C and Ranis., 1964: Development of the Labor Surplus Economy, Illinois.
5Michael P.Todaro, 1969: A model of Labor Migration and Urban Unemployment in Less Developed Countries, American Economic Review, Vo1.59, No. 1, pp138~148.