APA Style
Wittkopf, E, R., Kegley, C, W. (1989.).
World Politics : trend and transformation. (3rd ed.).
New York.:
St. Martin\' s Press..
MLA Style
Wittkopf, Eugene, R.., Kegley, Chales, W..
"World Politics : trend and transformation.".
3rd ed.
New York.:
St. Martin\' s Press.,
1989..
หนังสือ (Book).