“Possibilities for application of coal mining by rotary drilling at the opencast mine Gračanica-Gacko: Mogućnost primene eksploatacije uglja rotacionim bušenjem na površinskom kopu Gračanica-Gacko”, ume, no. 18, pp. 77–83, June 2011, Accessed: Nov. 14, 2026. [Online]. Available: https://ume.rgf.bg.ac.rs/index.php/ume/article/view/96