Arabzad, S. Mohammad, Hadi Shirouyehzad, Mahdi Bashiri, Reza Tavakkoli-Moghaddam, and Esmaeil Najafi. “Rebalancing Static Bike-Sharing Systems: A Two-Period Two-Commodity Multi-Depot Mathematical Model”. Transport 33, no. 3 (August 20, 2018): 718-726. Accessed September 17, 2019. https://journals.vgtu.lt/index.php/Transport/article/view/1558.