Jing Zhang and  Jie Chen,  Optimal Location of the I/O Point in the Parking System.   journal   = {International Journal of Mathematical and Computational Sciences}, [online]. World Academy of Science, Engineering and Technology.
    January 2019, vol. 146(2). 40 - 43
    [viewed 23 September 2019]. Available from: https://publications.waset.org/pdf/10010080.