1. Department of Mathematics, College of Science and Arts, Najran University, P.O. Box 1988, Najran, Saudi Arabia
2. Department of Mathematics, Faculty of Applied Science, Taiz University, P.O. Box 6169, Taiz, Yemen
3. Department of Mathematics, Faculty of Art and Sciences, Manisa Celal Bayar University, 45140 Manisa, Turkey
4. Department of Mathematics, Faculty of Sciences, Cankaya University, 06530 Ankara, Turkey
5. Institute of Space Sciences, Magurele-Bucharest, Romania