APA (7th ed.) Citation

De Voto, B. (1984). The portable Mark Twain. Penguin Books.

Chicago Style (17th ed.) Citation

De Voto, Bernard. The Portable Mark Twain. London: Penguin Books, 1984.

MLA (9th ed.) Citation

De Voto, Bernard. The Portable Mark Twain. Penguin Books, 1984.

Warning: These citations may not always be 100% accurate.