1. Department of Mathematics, Al-Qunfudah University College, Umm Al-Qura University, Mecca, Saudi Arabia
2. Department of Mathematics, Faculty of Science, Fayoum University, Fayoum, Egypt
3. Department of Mathematics (Statistics Option) Programme, Pan African University, Institute for Basic Science, Technology, and Innovation (PAUSTI), Nairobi, Kenya
4. Department of Mathematics, Faculty of Science, Helwan University, Cairo, Egypt