2Bergstrand,J.H.,“The Generalized Gravity Equation,Monopolistic Competition and the Factor Proportions Theory in International Trade,”The Review of Economics Statistics,1989,71(1):143-153.
3Linnemann,H.An Econometric Study in International Trade Flow,Amsterdam:Elsevier,1966.
4Poyhonen,Pentti,“A Tentative Model for the Volume of Trade between Countries,”Weltwirtschaflichhes Archive,1963,90(1):93-100.
5Tinbergen,Shaping the World Economy:Suggestions for an International Economic Policy,New York:The Twentieth Century Fund,1962.