Bateman & Crant 1993, p.103-118. Bateman, T. S.; Crant, J. M. (1993). "The proactive component of organizational behavior: A measure and correlates". Journal of Organizational Behavior. 14 (2): 103–118. doi:10.1002/job.4030140202.
Whiteley, Paul L.; Blankfort, Gerald (1933), "The Influence of Certain Prior Conditions Upon Learning", Journal of Experimental Psychology, 16 (6), APA: 843–851, doi:10.1037/h0075141