APA (7th ed.) Citation

Titley, P., Evans, H., & Petts, K. (1978). The middle ages (1. publ.). Owlet books.

Chicago Style (17th ed.) Citation

Titley, Paul, Hilary Evans, and Ken Petts. The Middle Ages. 1. publ. London [u.a.]: Owlet books, 1978.

MLA (9th ed.) Citation

Titley, Paul, et al. The Middle Ages. 1. publ. Owlet books, 1978.