1. Department of Mathematics, Riphah International University (Lahore Campus), Lahore 54000, Pakistan
2. Department of Mathematics, Aden University, Aden, P. O. Box 6014, Yemen
3. Department of Computer Sciences, College of Computer and Information Sciences, Princess Nourah bint Abdulrahman University, P.O.Box 84428, Riyadh 11671, Saudi Arabia
4. Department of Operations Research and Statistics, Faculty of Organizational Sciences, University of Belgrade, Belgrade, Serbia
5. School of Economics & Management, Nanchang Hangkong Universtiy, Nanchang 330036, China