1. Department of Statistics, St. Anthony's College, Shillong, India
2. School of Mathematics, Yunnan Normal University, Kunming, People's Republic of China
3. School of Mathematics and Statistics, Xi'an Jiaotong University, Xi'an, People's Republic of China
4. Department of Statistics, Faculty of Science, King Abdulaziz University, Jeddah, Kingdom of Saudia Arabia
5. Department of Statistics, Faculty of Commerce, Zagazig University, Zagazig, Egypt