1. College of Modern Economics and Management, Jiangxi University of Finance and Economics, Nanchang, Jiangxi, China
2. Department of Statistics, Yazd University, P.O. Box 89175-741, Yazd, Iran
3. Department of Statistics, Mathematics and Insurance, Benha University, Benha, Egypt
4. Laboratory of Probability and Statistics University of Badji Mokhtar, Annaba, Algeria