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