1. Department of Mathematics & Statistics, Riphah International University, Islamabad, Pakistan
2. Department of Mathematical Sciences, BUITEMS, Quetta, Pakistan
3. Department of Mathematics and Statistics, The University of Haripur, Haripur, KPK, Pakistan
4. Department of Mathematics, College of Science, Taif University, Taif, Saudi Arabia
5. Department of Mathematics, College of Sciences, King Khalid University, Abha, Saudi Arabia