1. Department of Mathematics, Faculty of Sciences, University of Nouakchott Al Aasriya, Nouakchott Bp 6093, Mauritania
2. Department of Mathematics and Statistics, College of Science, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh 11432, Saudi Arabia
3. Department of Applied Mathematics, National Research Centre, Cairo 12622, Egypt
4. Beheer en Algemene Directie, Ghent University Hospital, Corneel Heymanslaan 10, B-9000 Ghent, Belgium
5. Research Department, Ghent University, Sint-Pietersnieuwstraat 25, B-9000 Ghent, Belgium
6. Department of Computational Mathematics and Computer Science, Institute of Natural Sciences and Mathematics, Ural Federal University, 19 Mira St., Yekaterinburg 620002, Russia
7. Department of Mathematics, Faculty of Science, Benha University, Benha 13511, Egypt