4Walsh K.Trade in Services: Does Gravity Hold- AGravity Model Approach to Estimating Barriers toServices Trade [R]. IIIS Discussion Paper, No. 183,2006. 被引量：1
5Lee K . The Gravity Equation in International Trade inServices [C]. Paper presented at the European TradeStudy Group Conference,2004. 被引量：1
6Bergstrand J H. The Generalized Gravity Equation,Monopolistic Competition, and the Factor- ProportionsTheory in International Trade [J]. The Review ofEconomics and Statistics, 1989( 1): 143-153. 被引量：1
7Nunn N. Relationship -Specificity,Incomp; eteContracts, and the Pattern of Trade [J]. The QuarterlyJournal of Economic,2007(2) :569-600. 被引量：1
