Author(s):
1. Rada Petrovic, Faculty of Technology Banja Luka, Republic of Srpska, Bosnia and Herzegovina
2. Jelena Penavin-Škundrić, Prirodno-matematički fakultet Banja Luka, Republic of Srpska, Bosnia and Herzegovina
3. Branko Škundrić, Akademija nauka i umjetnosti Republike Srpske, Republic of Srpska, Bosnia and Herzegovina
4. Zorica Levi, Faculty of Technology Banja Luka, Republic of Srpska, Bosnia and Herzegovina
5. Dragica Lazić, Republic of Srpska, Bosnia and Herzegovina
6. Darko Bodroža, Republic of Srpska, Bosnia and Herzegovina
7. Gordana Ostojic, Republic of Srpska, Bosnia and Herzegovina