M. R. Mahadi and N. Ismail, “Utilization of Recycle Plastic Bottle Caps as Partial Replacement in Mortar”, rtcebe, vol. 4, no. 3, pp. 611–616, Jan. 2024, Accessed: Aug. 15, 2026. [Online]. Available: https://periodical.uthm.edu.my/index.php/rtcebe/article/view/5989