1. Faculty of Basic Applied Sciences, Department of Mathematics, Air University, PAF Complex E-9, Islamabad 44000, Pakistan
2. Department of Mathematics and Sciences, College of Humanities and Sciences, Prince Sultan University, Riyadh 11586, Saudi Arabia
3. Department of Mathematics, Air University, PAF Complex E-9, Islamabad 44000, Pakistan
4. Department of Mathematics, Faculty of Science, The Hashemite University, P.O Box 330127, Zarqa 13133, Jordan