1. Marketing Department, Management School, Lancaster University, Lancaster, UK
2. Department of Statistics, Yazd University, P.O. Box 89175-741, Yazd, Iran
3. Department of Statistics, Faculty of Science, University of Tabuk, Tabuk, Saudi Arabia
4. Department of Mathematics, Al-Qunfudah University College, Umm Al-Qura University, Mecca, Saudi Arabia