1. Department of Mathematics, Islamia College Peshawar, Peshawar 25000, Khyber Pakhtunkhwa, Pakistan
2. Department of Mathematics, College of Science Al-Zulfi, Majmaah University, Al-Majmaah 11952, Saudi Arabia
3. Mathematics Department, Faculty of Science, University of Tabuk, Tabuk, Saudi Arabia
4. Department of Mathematics, Bonga University, Bonga, Ethiopia