Jin-Bao Zhao and  Wei Deng,  Multilevel Fuzzy Decision Support Model for China-s Urban Rail Transit Planning Schemes.   journal   = {International Journal of Mathematical and Computational Sciences}, [online]. World Academy of Science, Engineering and Technology.
    October 2011, vol. 58(10). 1560 - 1566
    [viewed 23 January 2020]. Available from: https://publications.waset.org/pdf/3937.