APA (7th ed.) Citation

Child, J., Kelly, N., & Whittock, M. (1992). The crusades. Heinemann.

Chicago Style (17th ed.) Citation

Child, John, Nigel Kelly, and Martyn Whittock. The Crusades. Oxford [u.a.]: Heinemann, 1992.

MLA (9th ed.) Citation

Child, John, et al. The Crusades. Heinemann, 1992.