1. Department of Mathematics, Al-Azhar University-Gaza, Gaza Strip, State of Palestine
2. Department Mathematical Sciences, Faculty of Sciences, Princess Nourah Bint Abdulrahman University, P. O. Box 84428, Riyadh 11671, Saudi Arabia
3. Department of Mathematics and Sciences, Prince Sultan University, P. O. Box 66833, Riyadh 11586, Saudi Arabia
4. Department of Medical Research, China Medical University, Taichung 40402, Taiwan