F. Scott Fitzgerald (2015). “Collected Letters of F. Scott Fitzgerald: From the author of The Great Gatsby, The Side of Paradise, Tender Is the Night, The Beautiful and Damned, The Love of the Last Tycoon, The Curious Case of Benjamin Button and many other notable works”, p.166, e-artnow
Pema Chodron (2007). “Always Maintain a Joyful Mind: And Other Lojong Teachings on Awakening Compassion and Fearlessness”, p.57, Shambhala Publications