1. Colin Campbell, ?Transcendence is as American as Ralph Waldo Emerson,?Psychology Today, April, 1974, pp. 37?38.
2. Thomas Keating, M. Basil Pennington, Thomas E. Clarke,Finding Grace at the center (Still River, Massachusetts: St. Bede Pub., 1978; Basil M. Pennington,Daily We Touch Him: Practical Religious Experiences (Garden City, New York: Doubleday & Co., 1979).
3. Keating, et al.,Finding Grace, pp. 35?47.
4. Daniel Goleman,The Varieties of Meditative Experience (New York: E.P. Dutton, 1977).
5. Chögyam Trungpa, ?Dathun Letter? (Unpublished paper edited from talks given at the second Vajradhatur Seminary at Snowmass, Colorado, September to November, 1974). See also hisCutting Through Spiritual Materialism (Berkeley: Shambhala, 1973).