1. a Department of Mathematics , Bhangar Mahavidyalaya, University of Calcutta , Vill+P.O.+P.S- Bhangar, Pin-743502, 24PGS (South) , West Bengal , India
2. b Department of Applied Mathematics with Oceanlogy and Computer Programming , Vidyasagar University , West Midnapur , West Bengal , India
3. c Department of Information Technology , Birla Institute of Technology (Deemed University) , Mesra, Ranchi , India
4. d Department of Mathematics , Jadavpur University , Kolkata-32 , India