E. Kusrini, Y. Muharam, R. Ricky, W. W. Prihandini, and A. Usman, “Modelling and Simulation of Acid Extraction of Lanthanum from Indonesian Low Grade Bauxite using Fixed-Bed Extractor ”, Eng. J., vol. 24, no. 4, pp. 315–325, Jul. 2020, doi: 10.4186/ej.2020.24.4.315.