Ullmann, W. (1965). A history of political thought: The middle ages. Penguin.
Chicagoスタイル(17版)引用形式Ullmann, Walter. A History of Political Thought: The Middle Ages. Harmondsworth: Penguin, 1965.
MLA(9版)引用形式Ullmann, Walter. A History of Political Thought: The Middle Ages. Penguin, 1965.
警告: この引用は必ずしも正確ではありません.