APA (7th ed.) Citation

Ritchie, W. F., & Ritchie, J. N. G. (1985). Celtic warriors. Shire.

Chicago Style (17th ed.) Citation

Ritchie, W. F., and J. N. G. Ritchie. Celtic Warriors. Princes Risborough: Shire, 1985.

MLA (9th ed.) Citation

Ritchie, W. F., and J. N. G. Ritchie. Celtic Warriors. Shire, 1985.