1. Department of Mathematics, Quaid-I-Azam University 45320, Islamabad 44000, Pakistan
2. Department of Mathematics, Huzhou University, Huzhou 313000, P. R. China
3. Hunan Provincial Key Laboratory of Mathematical Modeling, and Analysis in Engineering Changsha University of Science & Technology, Changsha 410114, P. R. China
4. Department of Mathematics and Statistics, Riphah International University I-14, Islamabad 44000, Pakistan
5. Department of Mathematics, Davangere University, Davangere 577007, India