APA (7th ed.) Citation

Keats, J., Forman, M. B., & Forman, H. B. (1935). The letters of John Keats (2d ed.). H. Milford, Oxford University Press.

Chicago Style (17th ed.) Citation

Keats, John, Maurice Buxton Forman, and H. Buxton Forman. The Letters of John Keats. 2d ed. [London], [New York]: H. Milford, Oxford University Press, 1935.

MLA (9th ed.) Citation

Keats, John, et al. The Letters of John Keats. 2d ed. H. Milford, Oxford University Press, 1935.