1. Department of Mathematics, Government College University, Faisalabad 38000, Pakistan
2. Department of Mathematics, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
3. Department of Mathematics, Faculty of Science and Arts, Düzce University, Düzce 81620, Turkey
4. Mathematics, College of Engineering & Science, Victoria University, P.O. Box 14428, Melbourne City, VIC 8001, Australia