WASET
    Magdi M. E. Zumrawi and  Mohamed Awad,  Estimation of Subgrade Resilient Modulus from Soil Index Properties.   journal   = {International Journal of Geological and Environmental Engineering}, [online]. World Academy of Science, Engineering and Technology.
    September 2017, vol. 129(9). 856 - 862
    [viewed 08 May 2024]. Available from: https://publications.waset.org/pdf/10008058.