1Lucas R., 1988,On the Mechanism of Economic Develop- ment, Journal of Monetary Economics, 22:13-42.
2Romer P M, 1990, Endogenous Technological Changer, Journal of Political Economy, 5 : 71-102.
3Benhabib, J. , M.M. Spiegel, 1994,The Role of Human Capital in Economic Development: Evidence from Aggregate Cross-Country Data, Journal of Monetary Economics, 34 (2): 143-173.