Huang Xiaoling and  Liu Lufeng,  Hub Port Positioning and Route Planning of Feeder Lines for Regional Transportation Network .   journal   = {International Journal of Environmental and Ecological Engineering}, [online]. World Academy of Science, Engineering and Technology.
    September 2014, vol. 92(8). 2715 - 2722
    [viewed 22 February 2020]. Available from: https://publications.waset.org/pdf/9999403.