APA (7th ed.) Citation

RISO, D. R. (1987). Personality types: Using the enneagram for self-Discovery. The Aquarian Press.

Chicago Style (17th ed.) Citation

RISO, Dan Richard. Personality Types: Using the Enneagram for Self-Discovery. Northamptonshire: The Aquarian Press, 1987.

MLA (8th ed.) Citation

RISO, Dan Richard. Personality Types: Using the Enneagram for Self-Discovery. The Aquarian Press, 1987.