1. Department of Mathematics, Faculty of Mathematical Sciences, University of Guilan, Rasht, Iran
2. Department of Mathematics, Faculty of Mathematical Sciences, University of Mazandaran, Babolsar, Iran
3. Department of Mathematics, Kuztown University of Pennsylvania, 15200 Kutztown Road, Kuztown, PA-19530, USA
4. Department of Mathematics, Faculty of Science, King Abdulaziz University, Jeddah-21589, Saudi Arabia
5. Department of Mathematics, Faculty of Science, Beni-Suef University, Beni-Suef, Egypt
6. Department of Mathematics, Faculty of Science for Girls, King Abdulaziz University, Jeddah, Saudi Arabia
7. Department of Mathematical Sciences, Delaware State University, Dover, DE 19901-2277, USA