1. Department of Mathematics, School of Science, University of Management and Technology, Lahore 54770, Pakistan
2. School of Mathematics and Staistics, Hunan Normal University, Changsha, Hunan 4100081, China
3. Department of Mathematics, School of Information Science and Engineering, Chengdu University, Chengdu 610106, China
4. Department of Mathematics, University of Tabuk, Tabuk, Saudi Arabia