E. Chaichana, T. Saowapark, K. Sukrat, C. Khanthong, T. Pathomnithipinyo, and A. Jaturapiree, “Biodiesel Production from Used Oils with Char Based Catalyst from Pomelo Peel Impregnated with KOH as a Catalyst ”, J. Adv. Dev. Eng. Sci., vol. 14, no. 39, pp. 31–45, Apr. 2024.