APA (7th ed.) Citation

Ullmann, W. e., Angold, M., & Dobson, B. (1967). The world of the middle ages. Paul Hamlyn.

Chicago Style (17th ed.) Citation

Ullmann, Walter ed, Michael Angold, and Barrie Dobson. The World of the Middle Ages. London: Paul Hamlyn, 1967.

MLA (9th ed.) Citation

Ullmann, Walter ed, et al. The World of the Middle Ages. Paul Hamlyn, 1967.