1. Academic Medical Centre; Department of Otorhinolaryngology; Meibergdreef 9, A2-234, 1105 Az Amsterdam Netherlands
2. University of Toronto; Department of Otolaryngology - Head and Neck Surgery; 117 King Street East 5th floor Oshawa ON Canada L1H 1B9
3. Chulalongkorn University; Department of Otolaryngology, Faculty of Medicine; Bangkok Thailand