1. Department of Mathematical Sciences, College of Applied Science, Umm Al-Qura University, Makkah, Saudi Arabia
2. Department of Mathematics, Shaheed Benazir Bhutto Women University, Peshawar, Pakistan
3. Department of Mathematics, College of Sciences, King Khalid University, Abha, Saudi Arabia
4. Department of Mathematics, Abdul Wali Khan University, Mardan, Pakistan
5. Department of Mathematics, Quaid-i-Azam University, Islamabad, Pakistan