APA (7th ed.) Citation

Harte, B., Twain, M., & Howell, J. (1927). Sketches of the sixties. J. Howell.

Chicago Style (17th ed.) Citation

Harte, Bret, Mark Twain, and John Howell. Sketches of the Sixties. San Francisco: J. Howell, 1927.

MLA (9th ed.) Citation

Harte, Bret, et al. Sketches of the Sixties. J. Howell, 1927.