APA (7th ed.) Citation

Twain, M. 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.

MLA (9th ed.) Citation

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