Ahmad, W., and M. J. Khan. “Petrography of The Upper Litra and Chaudhwan Formations, Upper Siwalik Group, Zinda Pir Anticline, Northern Sulaiman Range”. Journal of Himalayan Earth Sciences, vol. 24, no. 1, Nov. 1991, pp. 191-02, http://ojs.uop.edu.pk/jhes/article/view/1402.