1. Department of Mathematics, Faculty of Science-Blqarn Campus, Bisha University, Saudi Arabia
2. Department of Mathematics, Faculty of Science-AL Faisaliah Campus, King Abdulaziz University, Jeddah, Saudi Arabia
3. Department of Physics, Chemistry and Mathematics, Alabama A&M University, Normal, AL-35811, USA
4. Department of Mathematical Sciences, Delaware State University, Dover, DE 19901-2277, USA