A. N. Zainuddin, M. . Mukri, and Norbaya Sidek, “Investigation on Soil Strength and Microstructure of Palm Oil Boiler Ash with Sodium Hydroxide and Sodium Silicate as Alkaline Solution”, ijscet, vol. 13, no. 1, pp. 57–67, May 2022, Accessed: Jul. 18, 2024. [Online]. Available: https://publisher.uthm.edu.my/ojs/index.php/IJSCET/article/view/8254