1. Department of Mathematics, University of Mysore, Mysuru 570006, India
2. Department of Mathematics, Faculty of Science, University of Jeddah, Jeddah, Saudi Arabia
3. Department of Mathematics, Yuvarajas College, University of Mysore, Mysuru 570005, India
4. Department of Mathematics, School of Advanced Sciences, Vellore Institute of Technology (VIT) University, Vellore 632014, Tamil Nadu, India