1. Bernard, A.B., Jensen, J.B., et al.: Wholesalers and retailers in us trade. Am. Econ. Rev. 100(2), 408–413 (2010)
2. Han, M.: China EU trade crisis and rescue measures under the covid-19 epidemic. Theory J. 04, 76–84 (2022). (in Chinese)
3. Jin, Z., Xu, G., Zhang, L.: The air silk road and new opportunities for cross border e-commerce development: a review of the third china international air logistics development conference 2018. Zhengzhou Aviat. Ind. Manage. College Newspaper 36(04), 8–13 (2018). (in Chinese)
4. Kou, Q.: The changes and future trends of china Europe economic and trade dependency. Eur. Stud. 40(01), 85–108+7 (2022). (in Chinese)
5. Liu, Y.: Northeast for the first time! cross border e-commerce packages board. the china Europe freight train to Germany. Shenyang Daily Newspaper (2022). (in Chinese)