APA (7th ed.) Citation

Miller, H., Schnellock, E., & Wickes, G. (1989). Letters to Emil. New Directions.

Chicago Style (17th ed.) Citation

Miller, Henry, Emil Schnellock, and George Wickes. Letters to Emil. New York: New Directions, 1989.

MLA (9th ed.) Citation

Miller, Henry, et al. Letters to Emil. New Directions, 1989.