f17.
Mihaly Csikszentmihalyi (2002), Flow, chapter 3, especially p 49. See also Mihaly Csikszentmihalyi (1975), Beyond Boredom and Anxiety; Mihaly Csikszentmihalyi (1996), Creativity; and the summary in Daniel Pink (2009), Drive: The Surprising Truth About What Motivates Us, chapter 5.