1. University of Cambridge School of Clinical Medicine Cambridge UK
2. Division of Library Services Office of Research Services, National Institutes of Health Bethesda Maryland U.S.A.
3. Department of Otolaryngology Head and Neck Surgery and Winship Cancer Institute, Emory University Atlanta Georgia U.S.A.
4. Department of Otolaryngology Head and Neck Surgery, Southern Illinois University Springfield Illinois U.S.A.