1. Department of Mathematics, COMSATS University Islamabad, Islamabad 44000, Pakistan
2. Department of Mathematics and Computer Science, University of Oradea, 1 University Street, 410087 Oradea, Romania
3. Department of Mathematics, College of Sciences and Arts Onaizah, Qassim University, P.O. Box 6640, Buraydah 51452, Saudi Arabia
4. Department of Electrical Engineering, College of Engineering, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia