Author(s):
1. Dragana Blagojević, Prirodno-matematički fakultet Banja Luka, Republic of Srpska, Bosnia and Herzegovina
2. Dragica Lazić, Faculty of Technology - University of East Sarajevo, Republic of Srpska, Bosnia and Herzegovina
3. Dragana Kešelj, Republic of Srpska, Bosnia and Herzegovina
4. Zoran Petrović, Faculty of Technology - University of East Sarajevo, Republic of Srpska, Bosnia and Herzegovina
5. Nebojša Vasiljević, Faculty of Technology - University of East Sarajevo, Republic of Srpska, Bosnia and Herzegovina