1. Perelman School of Medicine at the University of Pennsylvania Philadelphia Pennsylvania USA
2. Division of Rhinology Department of Otorhinolaryngology, Head and Neck Surgery University of Pennsylvania Philadelphia Pennsylvania USA
3. Division of Rhinology Department of Otorhinolaryngology, Head and Neck Surgery Medical University of South Carolina Charleston South Carolina USA
4. Division of Otolaryngology, Head and Neck Surgery Philadelphia Veterans Administration Medical Center Philadelphia Pennsylvania USA