TY - Front. Econ. China A1 - Haiwen Zhou T1 - International Trade with Increasing Returns in the Transportation Sector Y1 - 2014-12-11 JF - Frontiers of Economics in China JO - Front. Econ. China SP - 606 EP - 633 VL - 9 IS - 4 UR - https://academic.hep.com.cn/fec N1 - 10.3868/s060-003-014-0028-0 ER -