1. College of Mathematics and Systems Science, Shandong University of Science and Technology, Qingdao 266590, P. R. China
2. Nonlinear Analysis and Applied Mathematics (NAAM) — Research Group, Department of Mathematics, King Abdulaziz University, Jeddah 21589, Saudi Arabia
3. Department of Mathematics, Quaid-i-Azam University 45320, Isamabad 44000, Pakistan
4. Department of Mathematics, Swinburne University of Technology, Hawthorn, Victoria 3122, Australia