Gaya APA
Robertson, F., Marshall, F, C. (1975).
Historical Geology: Manual of Laboratory Excercise (3rd edition) .
:
Burgess Publishing Company.
Gaya MLA
Robertson, Forbes., Marshall, Frederick, C..
"Historical Geology: Manual of Laboratory Excercise (3rd edition)".
:
Burgess Publishing Company,
1975.
Text.