Working with the Enneagram - Mary Bast, Ph.D. 

http://www.breakoutofthebox.com

Enneagram Central - Clarence Thomson

http://www.enneagramcentral.com

Elizabeth Wagele 

http://www.wagele.com

Enneagram Monthly/publication 

http://www.ideodynamic.com/enneagram-monthly

EnneaMotion/Andrea Isaacs 

http://wee.ideodynamic.com/enneamotion

Enneagram-based Character Development Software

http://www.characterpro.com/

Carolyn Bartlett & John Reynolds, psychotherapists

http://www.insightforchange.com