WASET
    Z. Ulukan and  E. Demircioğlu,  A Survey of Discrete Facility Location Problems.   journal   = {International Journal of Industrial and Manufacturing Engineering}, [online]. World Academy of Science, Engineering and Technology.
    August 2015, vol. 103(7). 2487 - 2492
    [viewed 11 May 2024]. Available from: https://publications.waset.org/pdf/10002290.