J. Salimon and A. A. Ishak, “Optimization Process for Esterification of Rubber Seed Oil (RSO) with Trimethylolpropane (TMP)”, jst, vol. 4, no. 1, Mar. 2022, Accessed: Aug. 13, 2026. [Online]. Available: https://journal.uthm.edu.my/index.php/JST/article/view/470