APA (7th ed.) Citation

Reader's Digest. (1991). How to write and speak better. The Reader's Digest Ass'n.

Chicago Style (17th ed.) Citation

Reader's Digest. How to Write and Speak Better. London: The Reader's Digest Ass'n, 1991.

MLA (9th ed.) Citation

Reader's Digest. How to Write and Speak Better. The Reader's Digest Ass'n, 1991.