Mian, Ihsanullah, and Nusrat Jabeen. 1990. “Sodic Pyroxenes and Amphiboles from Koga Syenites of Ambela Granitic Complex, NWFP Pakistan”. Journal of Himalayan Earth Sciences 23 (1):67-85. http://ojs.uop.edu.pk/jhes/article/view/1374.