APA引文

Ullmann, W. (1965). History of Political Thought: The Middle Ages. Penguin.

Chicago Edition Citation

Ullmann, Walter. History of Political Thought: The Middle Ages. England: Penguin, 1965.

MLA引文

Ullmann, Walter. History of Political Thought: The Middle Ages. Penguin, 1965.

警告：這些引文格式不一定是100％准確.