Author(s):
1. Dragana Popara, Krajina Klas d.o.o. Banja Luka,
Republic of Srpska, Bosnia and Herzegovina
2. Milos Sorak, Faculty of Technology Banja Luka,
Republic of Srpska, Bosnia and Herzegovina
3. Miroslav Dragić, University of Banja Luka, Faculty of Technology,
Republic of Srpska, Bosnia and Herzegovina