Yan, Huang, Xiaoning Zhang, and Xiaolei Wang. “Hierarchical Passenger Hub Location Problem in a Megaregion Area Considering Service Availability”. Promet - Traffic&Transportation 33, no. 2 (March 31, 2021): 247-258. Accessed November 21, 2024. https://traffic.fpz.hr/index.php/PROMTT/article/view/3563.