APA (7th ed.) Citation

Moore, T. (1990). The harp that once through Tara's halls. Project Gutenberg.

Chicago Style (17th ed.) Citation

Moore, Thomas. The Harp That Once Through Tara's Halls. Champaign, Ill: Project Gutenberg, 1990.

MLA (9th ed.) Citation

Moore, Thomas. The Harp That Once Through Tara's Halls. Project Gutenberg, 1990.