1. Abrams, R. K. “International Trade Flows under Flexible Exchange Rates.”Economic Review, Federal Reserve Bank of Kansas City, March, 1980, pp. 3–10.
2. Aitken, N. D. “The Effect of the EEC and EFTA on European Trade: A Temporal Cross-Section Analysis,”American Economic Review, 63, 1973, pp. 881–92.
3. Anderson, James E. “A Theoretical Foundation for the Gravity Equation,”American Economic Review, 69, 1979, pp. 106–16.
4. Bergstrand, Jeffrey H. “The Gravity Equation in International Trade: Some Microeconomic Foundations and Empirical Evidence,”Review of Economic and Statistics, 67, 1985, pp. 474–81.
5. __ “The Generalized Gravity Equation, Monopolistic Competition, and the Factor-Proportions Theory in International Trade,”Review of Economic and Statistics, 71, 1989, pp. 143–53.