Salleh, Norhafizah, and Indriyani Puluhulawa. “Enhancement of Hybrid Beam Capacity With Glass Fiber Reinforced Polymer (GFRP): The Experimental Investigation into Metakaolin Substitution Effects”. International Journal of Sustainable Construction Engineering and Technology, vol. 16, no. 2, Dec. 2025, pp. 404-18, https://penerbit.uthm.edu.my/ojs/index.php/IJSCET/article/view/18413.