Harizan, Siti Haslina Md, and Syed Afzal Moshadi Shah. “Composite Sustainability Index for Online and Distance Education”. International Journal of Innovative Research and Scientific Studies 6, no. 4 (November 24, 2023): 1032–1040. Accessed May 19, 2024. https://www.ijirss.com/index.php/ijirss/article/view/2387.