Butt, K. A. (1981) “Pyrochlore Group Minerals in Carbonatites from Loe-Shilman, Khyber Agency, N.W.F.P.”, Journal of Himalayan Earth Sciences, 14(1), pp. 111-122. Available at: http://ojs.uop.edu.pk/jhes/article/view/1161 (Accessed: 29November2024).