1. Department of Mathematics and Statistics, International Islamic University, Sector H-10, Islamabad, Pakistan
2. Department of Mathematics and General Sciences, Prince Sultan University, P. O. Box 66833, Riyadh 11586, Saudi Arabia
3. Department of Medical Research, China Medical University, Taichung 40402, Taiwan
4. Department of Computer Science and Information Engineering, Asia University, Taichung, Taiwan
5. Department of Mathematics, Art and Science Faculty, Siirt University, TR-56100 Siirt, Turkey