APA (7th ed.) Citation

Dante & Sayers, D. L. (2006). The descent into hell XVIII. Penguin Books.

Chicago Style (17th ed.) Citation

Dante and Dorothy L. Sayers. The Descent into Hell XVIII. London: Penguin Books, 2006.

MLA (9th ed.) Citation

Dante and Dorothy L. Sayers. The Descent into Hell XVIII. Penguin Books, 2006.