Gaya APA
HOPPE, R. (1978).
E/MJ OPERATING HANDBOOK OF MINERAL SURFACE MINING AND EXPLORATION .
New York:
Mc Graw Hill.
Gaya MLA
HOPPE, RICHARD.
"E/MJ OPERATING HANDBOOK OF MINERAL SURFACE MINING AND EXPLORATION".
New York:
Mc Graw Hill,
1978.
Textbook.