Brad Warner (2010). “Zen Wrapped in Karma Dipped in Chocolate: A Trip Through Death, Sex, Divorce, and Spiritual Celebrity in Search of the True Dharma”, p.22, New World Library
Bruce D. Perry, Maia Szalavitz (2017). “The Boy Who Was Raised as a Dog: And Other Stories from a Child Psychiatrist's Notebook--What Traumatized Children Can Teach Us About Loss, Love, and Healing”, p.16, Hachette UK