Douglas McGregor, The Human Side of Enterprise: 25th Anniversary Printing (McGraw-Hill, 1985), p. 33–34.
55
Ryan & Deci, American Psychologist (January 2000).
56
Edward L. Deci and Richard M. Ryan, «Facilitating Optimal Motivation and Psychological Well-Being Across Life’s Domains,» Canadian Psychology, Vol. 49, No. 1 (Feb. 2008).