1. Barasat Cancer Research & Welfare Centre, West Bengal, India
2. Department of Otorhinolaryngology & Head Neck Surgery, M.G.M. Medical College & L.S.K. Hospital, Kishanganj, Bihar 855107, India
3. Department of Community Medicine, M.G.M. Medical College & L.S.K. Hospital, Kishanganj, Bihar 855107, India
4. M.G.M. Medical College & L.S.K. Hospital, Kishanganj 855107, India
5. College of Medicine & Sagore Dutta Hospital, Kamarhati, West Bengal, India