1. Department of Mathematics, University of Management and Technology, Lahore, Pakistan
2. Department of Mathematics, Cankaya University, Balgat, Ankara, Turkey + Institute of Space Sciences, Magurele, Bucharest, Romania + Department of Medical Research, China Medical University Hospital, China Medical University Taichung, Taichung, Taiwan
3. Department of Mathematics, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia Kingdom