APA (7th ed.) Citation

Chadwick, N. K. (1997). The Celts ([2a ed.].). Penguin Books.

Chicago Style (17th ed.) Citation

Chadwick, Nora K. The Celts. [2a ed.]. [London New York]: Penguin Books, 1997.

MLA (9th ed.) Citation

Chadwick, Nora K. The Celts. [2a ed.]. Penguin Books, 1997.