Author(s):
1. Danijela Nikolic, Faculty of Engineering, University of Kragujevac, Sestre Janjić 6, 34000 Kragujevac, Srbija 2IMW Ins, Serbia
2. Vanja Šušteršič, Serbia
3. Jasmina Skerlić, Faculty of Engineering, University of Kragujevac, Sestre Janjić 6, 34000 Kragujevac, Srbija 2IMW Ins, Serbia