APA (7th ed.) Citation

Twain, M., & DeVoto, B. (1974). Letters from the Earth. Harper & Row.

Chicago Style (17th ed.) Citation

Twain, Mark, and Bernard DeVoto. Letters from the Earth. New York: Harper & Row, 1974.

MLA (8th ed.) Citation

Twain, Mark, and Bernard DeVoto. Letters from the Earth. Harper & Row, 1974.