Thong-Innatra, Kappaput, Gritsanaruk Theeraraj, Chumporn Yuwaree, Kitikorn Charmondusit, and Rungjarat Hutacharoen. “A Study of Biodiesel (Ethyl Ester) Production from Grease/Oil Rich Sludge through Acid-Catalytic Ethanol Transesterification and It’s Fuel Specifications”. Environment and Natural Resources Journal 8, no. 2 (April 9, 2017): 31–46. Accessed May 7, 2024. https://ph02.tci-thaijo.org/index.php/ennrj/article/view/82555.