El-sawalhi, Nabil, and Ramy Lafy. “The Relationship Between Projects Management Managers’ Competencies and Employees’ Performance of Construction Industry at Gaza Strip”. International Journal of Sustainable Construction Engineering and Technology, vol. 12, no. 2, July 2021, pp. 38-52, https://penerbit.uthm.edu.my/ojs/index.php/IJSCET/article/view/2230.