Dr. Quddus Khan, PhD, is a senior assistant professor in the Department of Maths., Shibli National P. G. College, Azamgarh (UP), India. He has been teaching undergraduate and postg...ver maisDr. Quddus Khan, PhD, is a senior assistant professor in the Department of Maths., Shibli National P. G. College, Azamgarh (UP), India. He has been teaching undergraduate and postgraduate classes for the last sixteen years. Dr. Khan has to his credit sixteen research papers published in various national and international journals and has coauthored three books, authored three books, and produced two PhDs.ver menos