Baig, M. A. A., and M. ujeeb Ahmad. “Identification of Kaolin Polytypes and Other Minerals in Sediments of Thar Coal Field, Sindh, Pakistan”. Biological Sciences - PJSIR, vol. 50, no. 6, Dec. 2007, pp. 355-63, https://v2.pjsir.org/index.php/biological-sciences/article/view/1039.