David Deida (2008). “The Way of the Superior Man: A Spiritual Guide to Mastering the Challenges of Women, Work, and Sexual Desire: Easyread Super Large 24pt Edition”, p.32, ReadHowYouWant.com
Pema Chodron (2007). “Always Maintain a Joyful Mind: And Other Lojong Teachings on Awakening Compassion and Fearlessness”, p.85, Shambhala Publications