1. Department of ENT, Atal Bihari Vajpayee Institute of Medical Sciences and Dr. Ram Manohar Lohia Hospital, Connaught Place, Delhi, India,
2. Department of ENT, Sharda School of Medical Sciences and Research, Greater Noida, Uttar Pradesh, India,
3. Yatharth Hospital, Sector 110, Noida, Uttar Pradesh, India,
4. Department of ENT, SMS & R, Sharda University, Greater Noida, Uttar Pradesh, India,