APA (7th ed.) Citation

Keats, J. (1964). They fought alone. Secker & Warburg.

Chicago Style (17th ed.) Citation

Keats, John. They Fought Alone. London: Secker & Warburg, 1964.

MLA (9th ed.) Citation

Keats, John. They Fought Alone. Secker & Warburg, 1964.