Baron, Renee. What Type Am I? Discover Who You Really Are. New York: Penguin Books, 1998.

Espeland, Pamela. Knowing Me, Knowing You: The I-Sight Way to Understand Yourself and Others. Minneapolis, MN: Free Spirit, 2001.

Keirsey, David. Please Understand Me II: Temperament Character Intelligence. Prometheus Nemesis Book Co., 1998.

Kroeger, Otto, and Janet M. Thuesen. Type Talk: The 16 Personality Types That Determine How We Live, Love, and Work. New York: Dell Publishing, 1988.

Tieger, Paul D., and Barbara Barron-Tieger. Do What You Are. New York: Little, Brown & Co., 2001.

American Psychological Association www.apa.org Psychology research, news, and more

Dr. C. George Boeree, Psychology Department, Ship-pensburg University www.ship.edu Good overviews on the various personality theories and the major players, as well as some links to other sources

CPP, Inc. www.cpp.com Publisher and provider of products and services for professionals focused on meeting individual and organizational development needs; publishes and administers the MBTI and other instruments

The Enneagram www.ennea.com Web site devoted to the Enneagram offering information, books, and other resources.

Keirsey.com www.keirsey.com David Keirsey's Web site explains the Keirsey Temperament Sorter and offers his publications for sale.

The Myers & Briggs Foundation www.myersbriggs.org Books and other information about the Myers-Briggs Type Indicator

9Types.com www.9types.com Information on the Enneagram

The Personality Project www.personality-project.org General and academic information and links to personality research