1. Department of Mathematics, Department of mathematics, University of Faisalabad, Faisalabad
2. Department of Meteorology, COMSATS University, Islamabad, Pakistan
3. Department of Mathematics, College of Sciences, Khalid University Abha, Saudi Arabia
4. Department of Mathematics and Sciences, Prince Sultan University, P.O. Box 66833, 11586 Riyadh, Saudi Arabia
5. Department of Medical Research, China Medical University, Taichung 40402, Taiwan