1. College of Science, China University of Petroleum (East China), Qingdao 266580, P. R. China
2. Key Laboratory of Unconventional Oil and Gas Development, China University of Petroleum (East China), Ministry of Education, Qingdao 266580, P. R. China
3. Nonlinear Analysis and Applied Mathematics (NAAM)-Research Group, King Abdulaziz University, Jeddah, Saudi Arabia
4. Department of Mathematics, Quaid-i-Azam University 45320, Islamabad 44000, Pakistan