Gaya APA
Hoppe, R. (1978).
Operating Handbook of Mineral Surface Mining & Exploration, Vol 2. .
United States of America:
McGraw-Hill Book Company.
Gaya MLA
Hoppe, Richard..
"Operating Handbook of Mineral Surface Mining & Exploration, Vol 2.".
United States of America:
McGraw-Hill Book Company,
1978.
Text.