APA (7th ed.) Citation

Abulafia, D. (1988). Frederick II: A medieval emperor. Allen Lane The Penguin Press.

Chicago Style (17th ed.) Citation

Abulafia, David. Frederick II: A Medieval Emperor. London: Allen Lane The Penguin Press, 1988.

MLA (9th ed.) Citation

Abulafia, David. Frederick II: A Medieval Emperor. Allen Lane The Penguin Press, 1988.

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