6Caballe, Jordi and Manuel S. Santos, 1993, “On endogenous growth with physical and human capital”, Journal of Political Economy 101(6), 1042-1067.
7Schultz, Theodore W. , 1993, “The economic importance of human capital in modemization”, Education Economics 1 (1), 13 - 19.
8Lucas, Robert E. , 1993, “Making a miracle”, Econometrica 61 (2), 251 - 272.
9Benhabib. Jess and Mark Spiegel, 1994, “The role of human capital in economic development: evidence from aggregate cross country data”, Journal of Monetary Economics 34, 143 - 179.
10Robin M. Grier, 2000, “On the interaction of human and physical capital in Latin America”, NBER Working Paper.