8Clark, C. , L. Rewritten. The Conditions of Economic Progress [M]. London : Macmillan, 1957.
9Ellison, G. , E. L. Glaeser. The geographic concentration of industry: Does natural advantage explain agglomeration? [J]. American Economic Review, 1999, (2).
10Arrow,K. J. The economic implications of learning by doing[J]. The Review of Economic Studies, 1962, ( 3 ).