1. DEPARTMENT OF MATHEMATICS; ANANDA CHANDRA COLLEGE; JALPAIGURI; INDIA
2. ADVANCED COMPUTING & MICROELECTRONICS UNIT; INDIAN STATISTICAL INSTITUTE; KOLKATA; INDIA
3. DEPARTMENT OF MATHEMATICS; JADAVPUR UNIVERSITY; KOLKATA; INDIA
4. DEPARTMENT OF MATHEMATICS; UNIVERSITY OF NORTH BENGAL; WEST BENGAL; INDIA