Market Structure and Foreign Trade: Increasing Returns, Imperfect Competition, and the International Economy
E. Helpman and P. Krugman. Cambridge: MIT Press. 1985.
Scale Economies, Product Differentiation, and the Pattern of Trade
P. Krugman. The American Economic Review. vol. 70, no. 5. pp. 950-959. 1980.
A Model of Balance-of-Payments Crises
P. Krugman. Journal of Money, Credit, and Banking. vol. 11, no. 3. pp. 311-325. 1979.