APA (7th ed.) Citation

Keen, M. (1969). The Pelican history of medieval Europe. Penguin Books.

Chicago Style (17th ed.) Citation

Keen, Maurice. The Pelican History of Medieval Europe. Harmondsworth: Penguin Books, 1969.

MLA (9th ed.) Citation

Keen, Maurice. The Pelican History of Medieval Europe. Penguin Books, 1969.

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