Mihai Rebenciuc and  Simona Mihaela Bibic,  Generalized Rough Sets Applied to Graphs Related to Urban Problems.   journal   = {International Journal of Mathematical and Computational Sciences}, [online]. World Academy of Science, Engineering and Technology.
    August 2017, vol. 129(9). 411 - 416
    [viewed 26 April 2024]. Available from: https://publications.waset.org/pdf/10007960.