APA (7th ed.) Citation

Twain, M. (1988). Mark Twain's letters. Univ. of California Press.

Chicago Style (17th ed.) Citation

Twain, Mark. Mark Twain's Letters. Berkeley u.a: Univ. of California Press, 1988.

MLA (9th ed.) Citation

Twain, Mark. Mark Twain's Letters. Univ. of California Press, 1988.