Ardan, S. ., Putra, A., DJ, L., Sundari, R., Etika, S. B. ., & Nizar, U. K. (2019). THE STUDY OF REUSED SILICA-TITANIA CATALYST ON BIODIESEL PRODUCTION IN VARIOUS REACTION TIMES. International Journal of Advances in Scientific Research and Engineering (IJASRE), ISSN:2454-8006, DOI: 10.31695/IJASRE, 5(8), 133–141. https://doi.org/10.31695/IJASRE.2019.33458