1. Division of Pediatric Pulmonology, Department of Pediatrics and Adolescent Medicine Mayo Clinic Children's Center Rochester Minnesota U.S.A.
2. Division of Pediatric Otolaryngology, Head and Neck Surgery Cincinnati Children's Hospital Medical Center Cincinnati Ohio U.S.A.
3. Division of Pediatric Pulmonology, Department of Pediatrics Children's Hospital of Philadelphia Philadelphia Pennsylvania U.S.A.
4. Department of Otolaryngology–Head and Neck Surgery University of Colorado Aurora Colorado U.S.A.
5. Division of Pediatric Otolaryngology Children's Hospital Colorado Aurora Colorado U.S.A.
6. Division of Pediatric Gastroenterology, Hepatology and Nutrition, Department of Pediatrics Children's Hospital Boston Boston Massachusetts U.S.A.
7. Division of Pediatric Otolaryngology, Department of Otolaryngology–Head and Neck Surgery Stanford University School of Medicine Stanford California U.S.A.
8. Division of Pediatric Otolaryngology, Department of Pediatrics Monroe Carell Jr Children's Hospital at Vanderbilt Nashville Tennessee U.S.A.
9. Department of Otorhinolaryngology Mayo Clinic School of Medicine Rochester Minnesota U.S.A.