Akif, M., and M. Zubair. “PRODUCTION OF ALUMINIUM SULPHATE AND UTILIZATION OF CLAY RESIDUE FROM KAOLINITE CLAY”. Biological Sciences - PJSIR, vol. 47, no. 3, June 2004, pp. 183-6, https://v2.pjsir.org/index.php/biological-sciences/article/view/1514.