6Tinbergen J.Shaping the World Economy:Suggestion for an International Economic Policy[M].New York:The Twentieth Century Fund,1962.
7Anderson J E.A Theoretical Foundation for the Gravity Equation[J].American Economic Review,1979,69(1):106-116.
8Bergstrand J H.The Generalized Gravity Equation,Monopolistic Competition and the Factor-proportions Theory in International Trade[J].Review of Economic and Statistics,1989,71(1):143-153.
9Anderson J E,Wincoop V E.Gravity with Gravitas:A Solution to the Border Puzzle[J].American Economic Review,2003,93(1):170-192.
10Taylor C R,Franke G R,Bang H K.Use and Effectiveness of Billboards:Perspectives from Selective-perception Theory and Retail-gravity Models[J].Journal of Advertising,2006,35(4):21-34.