1. School of Medicine, Department of Otorhinolaryngology and Head and Neck Surgery, Sisters of Mercy University Hospital Center, University of Zagreb, Zagreb, Croatia
2. School of Medicine, Department of Otorhinolaryngology and Head and Neck Surgery, University of Mostar, Mostar, Bosnia and Herzegovina
3. School of Medicine, Croatian Health Insurance Fund, Zagreb, Croatia
4. School of Dental Medicine, Dental Clinic Apolonia, Zagreb, Croatia