Chogyam Trungpa (2010). “The Collected Works of Chogyam Trungpa: Volume Three: Cutting Through Spiritual Materialism; The Myth of Freedom; The Heart of the Bud dha; Selected Writings”, p.232, Shambhala Publications
Chogyam Trungpa (2010). “The Collected Works of Chogyam Trungpa: Volume Two: The Path Is the Goal; Training the Mind; Glimpses of Abhidharma; Glimpses of Shu nyata; Glimpses of Mahayana; Selected Writings”, p.16, Shambhala Publications