Shahdan, Siti Nurzubaida, and Radin Siti Fazlina Nazrah Hirzin. 2021. “Pre-Treatment of Used Cooking Oil Followed by Transesterification Reaction in the Production of Used Cooking Oil-Based Polyol”. Scientific Research Journal 18 (2):129-46. https://doi.org/10.24191/srj.v18i2.13749.