Author(s):
1. Jelena Isailović, Mining institute, Belgrade, Serbia, Serbia
2. Jasna Đerisilo, Serbia
3. Miloš Gajić, Mining institute, Belgrade, Serbia, Serbia
4. Sandra Petković Papalazarou, Mining institute, Belgrade, Serbia, Serbia
5. Josip Išek, Mining institute, Belgrade, Serbia, Serbia
6. Miroslav Sofrenić, Mining institute, Belgrade, Serbia, Serbia