Gaya APA
Ling, F, W., Duff, P. (2002).
Obstetrics & Gynecology ; principles for practice study guide .
Amerika:
McGraw-Hill.
Gaya MLA
Ling, Frank, W.., Duff, Patrick.
"Obstetrics & Gynecology ; principles for practice study guide".
Amerika:
McGraw-Hill,
2002.
Text.