APA (7th ed.) Citation

O'Brien, H. The Round Towers of Ireland; or, The History of the Tuath-De-Danaans.

Chicago Style (17th ed.) Citation

O'Brien, Henry. The Round Towers of Ireland; or, The History of the Tuath-De-Danaans.

MLA (9th ed.) Citation

O'Brien, Henry. The Round Towers of Ireland; or, The History of the Tuath-De-Danaans.

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