1. Division of Mathematics, School of Advance Sciences, Vellore Institute of Technology Chennai, Tamilnadu-600127, INDIA
2. Department of Mathematics, Sarala Birla University, Ranchi, INDIA
3. School of Mechanical Engineering, Vellore Institute of Technology, Chennai, INDIA
4. Department of Mathematics, Alipurduar University, Alipurduar, West Bengal-736121, INDIA