1. Department of Mathematics, Kuvempu University, Shankaraghatta, Shivamogga, Karnataka, India
2. Department of Mathematics, University of Calcutta, Ballygunge Circular Road, West Bengal, India
3. Department of Mathematics, BMS Institute of Technology and Management, Yelahanka, Bangalore, India
4. Department of Mathematics, Kuvempu University Shivamogga, Karnataka, India