1. College of Mechanical Engineering, Xijing University, Xi’an, China
2. Department of Mathematics, University of Management and Technology, Lahore, Pakistan
3. Department of Mathematics, National College of Business Administration & Economics, Lahore, Pakistan
4. School of Aerospace and Mechanical Engineering, Nanyang Technological University, Singapore
5. School of Mathematics, Northwest University, Xian, China
6. Department of Applied Mathematics, Northwestern Polytechnical University, Xian, China