1. Ministry of Transport of the People’s Republic of China: Statistical bulletin on the development of the transport industry in 2021. (in Chinese)
2. Guo, L.: Annual Report on Northeast China (2020). Social Sciences Academic Press (China), Beijing (2021). (in Chinese)
3. Alop, A.: The main challenges and barriers to the successful “smart shipping.” TransNav Int. J. Mar. Navig. Saf. Sea Transp. 13(3), 521–528 (2019)
4. Shi, W., Xiao, Y., Chen, Z., et al.: Evolution of green shipping research: themes and methods. Marit. Policy Manag. 45(7), 863–876 (2018)
5. Wang, L., Zhu, Y., Ducruet, C., Bunel, M., et al.: From hierarchy to networking: the evolution of the “twenty-first-century Maritime Silk Road” container shipping system. Transp. Rev. 38(4), 416–435 (2018)