APA (7th ed.) Citation

RISO & Hudson. (1996). Personality types: Using the enneagram for self-discovery. Houghton Mifflin.

Chicago Style (17th ed.) Citation

RISO and Hudson. Personality Types: Using the Enneagram for Self-discovery. New York: Houghton Mifflin, 1996.

MLA (9th ed.) Citation

RISO and Hudson. Personality Types: Using the Enneagram for Self-discovery. Houghton Mifflin, 1996.

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