1. Department of Statistics, Quaid-I-Azam University, Islamabad, Pakistan
2. Department of Mathematics, College of Sciences and Arts (Magardah), King Khalid University, Abha 61421, Saudi Arabia
3. Mathematics Department, College of Humanities and Science, Prince Sattam Bin Abdulaziz University, Al-Kharj, Saudi Arabia
4. Department of Mathematics, College of Sciences and Arts (Muhyil), King Khalid University, Abha 61421, Saudi Arabia