1. Department of Head and Neck SurgeryKaiser PermanenteOakland California U.S.A
2. Department of Otorhinolaryngology, Head and Neck Surgery , Multidisciplinary Sleep CenterUniversity Hospital AntwerpEdegem Belgium
3. the San Francisco, Department of Otolaryngology–Head and Neck SurgeryUniversity of CaliforniaSan Francisco California U.S.A
4. Advanced Ear, Nose & Throat Specialists, PCAtlanta Georgia U.S.A.