1. Department of Physics, Acharya Prafulla Chandra College, New Barrackpore, Kolkata 700131, India
2. Sadhanpur Uludanga Tulsiram High School (H.S), Amdanga, 24 Parganas (N) 743221, India
3. Department of Physics, Raghunathpur College, Purulia 723133, India