Dani, Dani Hari Tunggal Prasetiyo, et al. “Study of the Effect of NaOH Type Alkaline Catalyst on the Physicochemical Characteristics of Used Cooking Oil Biodiesel”. Jurnal Keteknikan Pertanian, vol. 12, no. 3, Dec. 2024, pp. 393-08, https://doi.org/10.19028/jtep.012.3.393-408.