Susmanto, P., Y. Gusman, M. F. Ridwan, and E. H. Tanara. “Characterization of Cr/SiO2/Al2O3 Catalyst from Rice Husk Using Impregnation Method”. Indonesian Journal of Chemical Analysis (IJCA), vol. 3, no. 1, Mar. 2020, pp. 33-39, doi:10.20885/ijca.vol3.iss1.art5.