1. University of Kragujevac, Faculty of Medical Sciences , Svetozara Markovica 69 , Kragujevac , Serbia
2. University of Kragujevac, Faculty of Medical Sciences, Department of Hygiene and Ecology , Svetozara Markovica 69 , Kragujevac , Serbia
3. Academy for Applied Studies Belgrade, Department of School of Applied Health Science Studies , Belgrade , Serbia