Feng, Shumin, Xianghao Shen, and Baoyu Hu. “Over-Supply in Public Transportation: Case Study of Bus and Metro Lines in Harbin City, China”. Promet - Traffic&Transportation 28, no. 5 (October 26, 2016): 471–477. Accessed August 27, 2025. https://traffic2.fpz.hr/index.php/PROMTT/article/view/2616.