2001: ISBN 1-57062-768-1* "Transformations of Consciousness: Conventional and Contemplative Perspectives on Development" (co-authors: Jack Engler, Daniel Brown), 1986, ISBN 0-394-74202-8* "Spiritual Choices: The Problem of Recognizing Authentic Paths to Inner Transformation" (co-authors: Dick Anthony, Bruce Ecker), 1987, ISBN 0-913729-19-1* "Grace and Grit: Spirituality and Healing in the Life of Treya Killam Wilber", 1991, 2nd ed.
2001: ISBN 1-57062-768-1* "Transformations of Consciousness: Conventional and Contemplative Perspectives on Development" (co-authors: Jack Engler, Daniel Brown), 1986, ISBN 0-394-74202-8* "Spiritual Choices: The Problem of Recognizing Authentic Paths to Inner Transformation" (co-authors: Dick Anthony, Bruce Ecker), 1987, ISBN 0-913729-19-1* "Grace and Grit: Spirituality and Healing in the Life of Treya Killam Wilber", 1991, 2nd ed.