Y. Fransiscus, R. K. Widi, G. O. Aprilasti, and M. D. Yuharma, “Adsorption of Phosphate in Aqueous Solutions Using Manganese Dioxide”, Int. J. Adv. Sci. Eng. Inf. Technol., vol. 8, no. 3, pp. 818–824, Jun. 2018.