Al-Emad, Nashwan Hamid, and Sasitharan Nagapan. “Identification of Delay Factors from Mecca’s Construction Experts Perspective”. International Journal of Sustainable Construction Engineering and Technology, vol. 6, no. 2, Sept. 2015, pp. 16-25, https://penerbit.uthm.edu.my/ojs/index.php/IJSCET/article/view/1126.