1. Institute of Trade and Economy, Siberian Federal University, 79 Svobodny Av., 660041 Krasnoyarsk, Russia
2. Open Pit Mining Department, T.F. Gorbachev Kuzbass State Technical University, 28 Vesennya St., 650000 Kemerovo, Russia
3. Institute of Earth Sources, Faculty of Mining, Ecology, Process Technologies and Geotechnology, Technical University of Košice, Letná, 9, 040 01 Košice, Slovakia