Pema Chodron (2007). “Always Maintain a Joyful Mind: And Other Lojong Teachings on Awakening Compassion and Fearlessness”, p.85, Shambhala Publications
William Shakespeare, Thomas Dolby (1872). “Dictionary of Shakespearian Quotations: Exhibiting the Most Forcible Passages, Illustrative of the Various Passions, Affections and Emotions of the Human Mind”, p.25