Shuma, H., L. Mkayula, and Y. Makame. “Assessment of the Effect of Acid Activation of Kaolin from Malangali on Water Defluoridation”. Tanzania Journal of Science, vol. 45, no. 2, Mar. 2021, pp. 279-96, http://tjs.udsm.ac.tz/index.php/tjs/article/view/220.