APA استشهاد

Gettell, R. G. (1964). History of political thought (2nd ed.).

استشهاد بنمط شيكاغو

Gettell, Raymond Garfield. History of Political Thought. 2nd ed. 1964.

MLA استشهاد

Gettell, Raymond Garfield. History of Political Thought. 2nd ed. 1964.