1. School of Mathematics and Statistics, Central South University, Changsha, P.R. China
2. Department of Mathematics, Women University of Azad Jammu and Kashmir, Bagh, Azad Kashmir, Pakistan
3. Department of Mathematics, Capital University of Science and Technology (CUST), Islamabad, Pakistan
4. Department of Mathematics, Faculty of Science, New Valley University, Al-Kharga, Al-Wadi Al-Gadid, Egypt
5. Department of Mathematics, Faculty of Science, Northern Border University, Arar, Saudi Arabia
6. Department of Mathematics, College of Science and Arts, Qassim University, Al-Badaya, Saudi Arabia
7. Department of Operations and Management Reseatch, Faculty of Graduate Studies for Statistical Research, Cairo University, Giza, Egypt