APA (7th ed.) Citation

Keats, J., Forman, M. B., & Forman, H. B. (1952). Letters (4th ed.). Oxford University Press.

Chicago Style (17th ed.) Citation

Keats, John, Maurice Buxton Forman, and H. Buxton Forman. Letters. 4th ed. London, New York: Oxford University Press, 1952.

MLA (9th ed.) Citation

Keats, John, et al. Letters. 4th ed. Oxford University Press, 1952.