1. Department of Otolaryngology−Head and Neck Surgery, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
2. Department of Otolaryngology, University of Arizona College of Medicine, Tucson
3. Department of Otolaryngology, University of Utah School of Medicine, Salt Lake City
4. Health Sciences Library, University of Arizona, Tucson
5. Division of Pediatric Otolaryngology−Head and Neck Surgery, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio
6. Division of Pulmonary Medicine, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio
7. Department of Otolaryngology−Head and Neck Surgery, University of Cincinnati, Cincinnati, Ohio