1. ENT Department, Christchurch Hospital, Christchurch, New Zealand
2. ENT Department, Guy's Hospital, London
3. Royal National Troat, Nose and Ear Hospital, London
4. Department of ENT–Head and Neck Surgery, Ng Teng Fong General Hospital, Singapore
5. Department of Otolaryngology, Charing Cross Hospital, London
6. ENT Department, Northwick Park Hospital, London.