1. Public Courses Education Department, Anhui Business Vocational College, Hefei, Anhui, China
2. Department of Mathematics, Faculty of Science, University of Gujrat, Gujrat, Pakistan
3. Department of Natural Sciences and Humanities, University of Engineering and Technology, Lahore (RCET), Pakistan
4. Mathematics Department, College of Science, King Saud University, Riyadh, Saudi Arabia