Author(s):
1. Aleksandar Grubić, Rudarski institut Prijedor, e-mail Save Kovačevića bb, Prijedor, Republic of Srpska, Bosnia and Herzegovina
2. Ranko Cvijić, Republic of Srpska, Bosnia and Herzegovina
3. Duško Vlačina, ArcelorMittal Prijedor, Republic of Srpska, Bosnia and Herzegovina

Abstract