Lu, Xiao-Shan, and Ren-Yong Guo. “A Bi-Objective Model for Siting Park-and-Ride Facilities With Spatial Equity Constraints”. Promet - Traffic&Transportation, vol. 27, no. 4, Aug. 2015, pp. 301-8, doi:10.7307/ptt.v27i4.1584.