APA (7th ed.) Citation

Riso, D. R. (1987). Personality types: Using the enneagram for self-discovery. Aquarian Press.

Chicago Style (17th ed.) Citation

Riso, Don Richard. Personality Types: Using the Enneagram for Self-discovery. Northamtonshire, Eng: Aquarian Press, 1987.

MLA (9th ed.) Citation

Riso, Don Richard. Personality Types: Using the Enneagram for Self-discovery. Aquarian Press, 1987.