Gurucharan Singh Khalsa, Ph.D., is an expert in the mind, a yogi, psychotherapist, teacher, and writer. He is president of a business consulting firm, Khalsa Consultants, Inc., and has taught kundalini yoga with Yogi Bhajan for over thirty years. He lives in Millis, Massachusetts.

Yogi Bhajan, Ph.D., is a Master of kundalini and tantric yoga. He is the spiritual leader of the Sikh religion in the Western Hemisphere. He inspired the creation of the family of Golden Temple natural products, including Yogi Tea and Peace Cereals. He lives in Espanola, New Mexico.