Селигман М. В поисках счастья. — М.: Манн, Иванов и Фербер, 2011. (Martin Seligman, Authentic Happiness: Using the New Positive Psychology to Realize Your Potential for Lasting Fulfillment. Free Press, 2004, p. 178). Paul R. Verkuil, Martin Seligman, & Terry Kang, «Countering Lawyer Unhappiness: Pessimism, Decision Latitude and the Zero-Sum Dilemma Cardozo Law School, Public Research Paper. No. 19 (September 2000).
