Mohamad Nordin, Nor Asikin, Nadia Farhana Adnan, Noraini Hamzah, Wan Nor Roslam Wan Isahak, Jumat Salimon, and Mohd Ambar Yarmo. “Monoestolides Synthesis From Ricinoleic-Oleic Acids Using Silicotungstic Acid Sol-Gel Catalyst”. Journal of Science and Technology 2, no. 2 (1). Accessed January 25, 2021. https://publisher.uthm.edu.my/ojs/index.php/JST/article/view/261.