Hu, Xiang, Eliza Nor, and Chee-Wooi Hooy. “Optimal Capital Structure of PPP Projects: A Review of the Literature”. Journal of Contemporary Issues and Thought 12, no. 2 (June 24, 2022): 1–8. Accessed April 20, 2024. https://ejournal.upsi.edu.my/index.php/JCIT/article/view/6966.