1Arthur, B. 1994, Increasing Returns and Path Dependence in the Economy,. Ann Arbor: Lniversity of Michigan Press.
2Chamberlin, E. 1950. Product Hetemgeneity and Public Policy. American Economic Review 40: p. 85.
3Dixit, A. K. and J. E. Stiglitz. 1977. Monopolistic Competition and Optimom Prodoct Diversity. American Economic Review, 67: 297-308
4Fujita, Masahisa. 1988. A Monopolistic Competition Model of Spatial Agglomeration: a Differentiated Products Appmach. Regional Science and Urban Economics. 18:87-124.
5Fujita,M., P. Krugman & A. Nenables 1999. The Spatial Economy: Cities, Regions, and Intenational Tmde. Cambridge: MIT Press.
6Grossman.G.,and E.Helpman.1991,Innovation and Growth in the World Economy. Cambridge: MIT Press.
7Helpman, E., and P. Krugman. 1985. Market Structure and Foreign Trade. Cambridge: MIT Press.
8Krugman.Panl.1980.Scale Economies.Production Differentiation,and the Pattern of Trade.American Economic Review.70:950-959.
9Krugman, Paul. 1991. Geography and Trade."Cambridge:MIT Press.
10Krugman, Paul. 1995. Development, Geography. and Economic Theory. Cambridge:MIT Press.