1. Department of Mathematics and Statistics, The University of Lahore, Lahore Campus, Lahore, Pakistan
2. Department of Mathematics, College of Science, King Saud University, P.O. Box 22452, Riyadh 11495, Saudi Arabia
3. Punjab Tianjin University of Technology, Lahore, Pakistan
4. Faculty of Science and Technology, University of the Faroe Islands, Faroe Islands, Denmark
5. Department of Applied Mathematics, Gono Bishwabidyalay University, Dhaka, Bangladesh