Gaya APA
Shorck, R, R., Twenhofel, W. (1953).
Principles of invertebrate paleontology (1953).
:
New York : McGraw Hill Book Co.,.
Gaya MLA
Shorck, Robert, R., Twenhofel, W.
"Principles of invertebrate paleontology".
1953
:
New York : McGraw Hill Book Co.,,
1953.
Text.