1. University of Jeddah, College of Science, Department of Mathematics, Jeddah, Saudi Arabia
2. Department of Mathematics and Statistics, The University of Lahore, Lahore 54000, Pakistan
3. Department of Humanities and Basic Sciences, MCS, National University of Sciences and Technology, Islamabad 44000, Pakistan
4. Department of Mathematics, Iran University of Science and Technology Narmak, Tehran 16844, Iran