1. Department of Statistics, Quaid-I-Azam University, Islamabad, Pakistan
2. Department of Mathematics, College of Sciences and Arts (Muhyil), King Khalid University, Muhyil, Saudi Arabia
3. Department of Mathematics and Computer, College of Sciences, Ibb University, Ibb, Yemen
4. College of Statistical Sciences, University of the Punjab, Lahore
5. Mathematics Department, Prince Sattam Bin Abdulaziz University, Al-Kharj, Saudi Arabia
6. Department of Statistics and Information, Sana’a University, Sana’a, Yemen