1. Jadran-Galenski Laboratorij d.d., Svilno 20, 51000 Rijeka, Croatia
2. Department of Otorhinolaryngology, Head and Neck Surgery, Sisters of Mercy University Hospital, 10000 Zagreb, Croatia
3. National State Research Institute of Ear, Throat, Nose and Speech, 190013 St. Petersburg, Russia
4. Morozov Children’s City Clinical Hospital, Russian National State Pirogov Medical University, 117437 Moscow, Russia
5. Regional Center of Traumatology and Ortopedics, Department of Otorhinolaryngology, Karaganda State Polyclinic, 100000 Karaganda, Kazakhstan
6. “Andrija Štampar” School of Public Health, School of Medicine, University of Zagreb, 10000 Zagreb, Croatia