APA (7th ed.) Citation

O'Brien, C. C. (1972). States of Ireland. Pantheon Books.

Chicago Style (17th ed.) Citation

O'Brien, Conor Cruise. States of Ireland. New York: Pantheon Books, 1972.

MLA (9th ed.) Citation

O'Brien, Conor Cruise. States of Ireland. Pantheon Books, 1972.

Warning: These citations may not always be 100% accurate.