1. Professor, Dept. of Mathematics, Quaid-I-Azam Univ., 45320, Islamabad 44000, Pakistan.
2. Ph.D. Scholar, Dept. of Mathematics, Quaid-I-Azam Univ., 45320, Islamabad 44000, Pakistan.
3. Ph.D. Scholar, Dept. of Mathematics, Quaid-I-Azam Univ., 45320, Islamabad 44000, Pakistan (corresponding author).
4. Professor, Nonlinear Analysis and Applied Mathematics (NAAM) Research Group, Dept. of Mathematics, Faculty of Science, King Abdulaziz Univ., P.O. Box 80203, Jeddah 21589, Saudi Arabia.