WASET
    S. Hasan and  I. Beshara,  Sustainable Maintenance Model for Infrastructure in Egypt.   journal   = {International Journal of Civil and Environmental Engineering}, [online]. World Academy of Science, Engineering and Technology.
    June 2020, vol. 163(7). 207 - 214
    [viewed 11 May 2024]. Available from: https://publications.waset.org/pdf/10011310.