APA (7th ed.) Citation

Ullmann, W. (1961). Principles of government and politics in the Middle Ages. Barnes & Noble.

Chicago Style (17th ed.) Citation

Ullmann, Walter. Principles of Government and Politics in the Middle Ages. New York: Barnes & Noble, 1961.

MLA (9th ed.) Citation

Ullmann, Walter. Principles of Government and Politics in the Middle Ages. Barnes & Noble, 1961.

Warning: These citations may not always be 100% accurate.