Csikszentmihalyi M. Flow: The Psychology of Optimal Experience. New York: Harper Perennial Modern Classics, 2008 [1990]. P. 186.
164
Thoreau H. D. The Writings of Henry David Thoreau: Journal, Ed. by Bradford Torrey. Journal IV: May 1, 1852 – February 27, 1853. Boston: Houghton Mifflin and Company, 1906. P. 397.