1. Faculty of Medicine, University of Novi Sad, Novi Sad, Serbia
2. Special Hospital for Rheumatic Diseases, Novi Sad, Serbia
3. Institute for Child and Youth Health Care of Vojvodina, Novi Sad, Serbia
4. Institute for Pulmonary Diseases of Vojvodina, Sremska Kamenica, Serbia
5. Health Center Bač, Bač, Serbia
6. Health Center Bački Petrovac, Bački Petrovac, Serbia