Mingliang Yang, Zeyuan Xiang, XiJun Xu, Chongren Gao, Liqin Guo, Fei Chen. “Comparison and Analysis of Logistics Ring Track in Plant Area”. Design Engineering, Vol. 2021, no. 02, Mar. 2021, pp. 421 -33, http://thedesignengineering.com/index.php/DE/article/view/1176.