APA (7th ed.) Citation

Twain, M., & Cox, J. M. (1984). Life on the mississippi. Penguin Books.

Chicago Style (17th ed.) Citation

Twain, Mark, and James M. Cox. Life on the Mississippi. New York: Penguin Books, 1984.

MLA (9th ed.) Citation

Twain, Mark, and James M. Cox. Life on the Mississippi. Penguin Books, 1984.