1. Internal Medicine Specialist-Rheumatologist, Institute of Rheumatology, University of Belgrade School of Medicine, Belgrade, Serbia.
2. University of East Sarajevo Medical Faculty, Republika Srpska, Lukavica, Bosnia and Herzegovina.
3. Bioptron AG, Wollerau, Switzerland.
4. Internal Medicine Specialist, University Clinical Hospital Center Zemun, University of Belgrade School of Medicine, Belgrade, Serbia.
5. Physical Medicine and Rehabilitation Specialist, The Belgrade City Institute of Gerontology, Belgrade, Serbia.