Gaya APA

E, G, R., Bullock, R, L. (1998). Techniques in Underground Mining . Colorado: Society for Mining, Metallurgy, and Exploration (SME).

Gaya MLA

E, Gertsch., Richard., Bullock, Richard, L. "Techniques in Underground Mining". Colorado: Society for Mining, Metallurgy, and Exploration (SME), 1998. Text.