1. Department of Mathematics and Statistics, Faculty of Science, Imam Mohammad Ibn Saud Islamic University, Riyadh 11623, Saudi Arabia
2. Department of Mathematics, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
3. Department of Mathematics, Wenzhou University, Wenzhou 325035, China
4. Ecole Normale Superieure, Department of Mathematics, Mostaganem 27000, Algeria
5. Dipartimento di Matematica e Informatica, Universitá di Catania, Catania, Italy
6. Faculty of Fundamental Science, Industrial University of Ho Chi Minh City, Vietnam