1. Military Medical Academy, Clinic for Pulmonology, Belgrade, Serbia + University of Defence, Faculty of Medicine of the Military Medical Academy, Belgrade, Serbia
2. University of Defence, Faculty of Medicine of the Military Medical Academy, Belgrade, Serbia + Military Medical Academy, Clinic for Emergency Internal Medicine, Belgrade, Serbia
3. Military Medical Academy, Clinic for Emergency Internal Medicine, Belgrade, Serbia
4. University of Defence, Faculty of Medicine of the Military Medical Academy, Belgrade, Serbia + Military Medical Academy, Clinic for Cardiology, Belgrade, Serbia
5. University of Belgrade, Institute for Biostatistics, Belgrade, Serbia
6. University of Kragujevac, Faculty of Medical Sciences, Department of Internal Medicine, Kragujevac, Serbia