1. Department of Mathematics, COMSATS University Islamabad, Islamabad 44000, Pakistan
2. Department of Mathematics, AL-Qunfudhah University college, Umm Al-Qura University, KSA
3. Facultad de Economíay Empresa and Multidisciplinary Institute of Enterprise (IME), University of Salamanca, 37007 Salamanca, Spain
4. Department of Electrical Engineering, College of Engineering, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia