1. University of Banja Luka, Faculty of Medicine, Banja Luka, Bosnia and Herzegovina, Banja Luka, Bosnia and Herzegovina + University Clinical Center of Republic of Srpska, Ear, Nose and Throat Department, Banja Luka, Bosnia and Herzegovina
2. University of Banja Luka, Faculty of Medicine, Banja Luka, Bosnia and Herzegovina, Banja Luka, Bosnia and Herzegovina + University Clinical Center of Republic of Srpska, Clinical Pathology Department, Banja Luka, Bosnia and Herzegovina
3. Institute for Physical Medicine and Rehabilitation "Dr Miroslav Zotović", Banja Luka, Bosnia and Herzegovina