APA (7th ed.) Citation

Ullmann, W. (1961). Principles of government and politics in the Middle Ages (1. ed.). Methuen.

Chicago Style (17th ed.) Citation

Ullmann, Walter. Principles of Government and Politics in the Middle Ages. 1. ed. London: Methuen, 1961.

MLA (9th ed.) Citation

Ullmann, Walter. Principles of Government and Politics in the Middle Ages. 1. ed. Methuen, 1961.