APA (7th ed.) Citation

Powell, T. G. E. (1958). The Celts. F.A. Praeger.

Chicago Style (17th ed.) Citation

Powell, T. G. E. The Celts. New York: F.A. Praeger, 1958.

MLA (8th ed.) Citation

Powell, T. G. E. The Celts. F.A. Praeger, 1958.