1. Department of Mathematics, University of the Punjab, Lahore, Pakistan
2. Department of Mathematics, Quaid-i-Azam University, Islamabad, Pakistan
3. Department of Mathematics, Wenzhou University, Wenzhou City, China
4. Department of Mathematics, Faculty of Science, University of Tabuk, Tabuk, Saudi Arabia
5. Department of Mathematics, Umm Al-Qura University, Makkah, Saudi Arabia