Nizam, Nurul Athirah, and Nurasyikin Misdan. “Review of The Production of Biodiesel from Waste Cooking Oil Using Acid Alkaline Based Catalysts”. Progress in Engineering Application and Technology, vol. 3, no. 1, June 2022, pp. 954-66, https://publisher.uthm.edu.my/periodicals/index.php/peat/article/view/6451.