APA (7th ed.) Citation

Funk & Lewis. (1971). 30 days to a more powerful vocabulary (Rev. ed.). Pocket Books.

Chicago Style (17th ed.) Citation

Funk and Lewis. 30 Days to a More Powerful Vocabulary. Rev. ed. New York: Pocket Books, 1971.

MLA (8th ed.) Citation

Funk and Lewis. 30 Days to a More Powerful Vocabulary. Rev. ed. Pocket Books, 1971.