Ardan, S. , Putra, A., DJ, L., Sundari, R., Etika, S.B. and 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 (Aug. 2019), 133–141. DOI:https://doi.org/10.31695/IJASRE.2019.33458.