A. Alatas, D. N. Putri, M. S. Perdani, T. S. Utami, and H. Hermansyah, “Biodiesel Synthesis through the Non-Alcohol Route using the Immobilized Lipase Enzyme from Bacillus subtilis as Biocatalyst”, Int. J. Adv. Sci. Eng. Inf. Technol., vol. 11, no. 3, pp. 1239–1245, Jun. 2021.