1. Department of Medical, Surgical, and Health Sciences, Section of Otolaryngology University of Trieste Trieste Italy
2. Department of ENT Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust Cambridge UK
3. University of Cambridge Medical Library Cambridge UK
4. Department of ENT/Head and Neck Surgery Queen Elizabeth University Hospital Birmingham Birmingham UK
5. Unit of Cancer Epidemiology Centro di Riferimento Oncologico di Aviano (CRO) IRCCS Aviano Italy