Thich Nhat Hanh (2011). “Your True Home: The Everyday Wisdom of Thich Nhat Hanh: 365 days of practical, powerful teaching s from the beloved Zen teacher”, p.21, Shambhala Publications
Albert Einstein (2015). “Bite-Size Einstein: Quotations on Just About Everything from the Greatest Mind of the Twentieth Century”, p.31, St. Martin's Press