WASET
    Sophia Hayes and  Kenny L. Liang and  Sahil Sharma and  Austin Shema and  Mahmoud Bader and  Mohamed Elbarkouky,  A Framework for Improving Trade Contractors’ Productivity Tracking Methods.   journal   = {International Journal of Civil and Environmental Engineering}, [online]. World Academy of Science, Engineering and Technology.
    January 2020, vol. 157(1). 52 - 64
    [viewed 27 April 2024]. Available from: https://publications.waset.org/pdf/10011022.