APA (7th ed.) Citation

Clemens, S. L., Howells, W. D., & Clark, C. H. (1969). Mark Twain's library of humor. Bonanza Books.

Chicago Style (17th ed.) Citation

Clemens, Samuel Langhorne, William Dean Howells, and Charles Hopkins Clark. Mark Twain's Library of Humor. New York: Bonanza Books, 1969.

MLA (9th ed.) Citation

Clemens, Samuel Langhorne, et al. Mark Twain's Library of Humor. Bonanza Books, 1969.