APA (7th ed.) Citation

Pound, E., Theobald, J., & Theobald, J. (1984). Letters (1. ed.). Black Swan Books.

Chicago Style (17th ed.) Citation

Pound, Ezra, John Theobald, and John Theobald. Letters. 1. ed. Redding Ridge: Black Swan Books, 1984.

MLA (9th ed.) Citation

Pound, Ezra, et al. Letters. 1. ed. Black Swan Books, 1984.