1. Department of Basic Sciences and Humanities, National University of Sciences and Technology, Islamabad, Pakistan
2. Department of Mathematics, Faculty of Science and Arts, Mahayl Assir, King Khalid University, Abha, Saudi Arabia
3. Department of Mathematics and Statistics, The University of Haripur, Haripur, Pakistan
4. Department of Mathematics and Computer, Faculty of Science, Ibb University, Ibb, Yemen
5. Department of Mathematics, Higher Institute of Engineering and Technology, King Marriott, Egypt, P.O. Box 3135, Egypt