1. Department of Mathematics, KPR Institute of Engineering and Technology, Coimbatore 641407, Tamil Nadu, India
2. Department of Mathematics, Kongu Engineering College, Erode 638060, Tamil Nadu, India
3. Department of Mathematical Sciences, United Arab Emirates University, P.O. Box 15551, AlAin, AbuDhabi, 15551, United Arab Emirates
4. PG and Research Department of Mathematics, Ramakrishna Mission Vivekananda College, Mylapore, Chennai 600004, Tamil Nadu, India