Murphy, Gardner (1947), "The Hierarchy of Conditionings.", Personality: A biosocial approach to origins and structure., New York: Harper & Brothers, pp. 224–246, doi:10.1037/10759-010, archived from the original on 2018-06-04, retrieved 2025-03-16
Murphy, Gardner (1947), "The Hierarchy of Conditionings.", Personality: A biosocial approach to origins and structure., New York: Harper & Brothers, pp. 224–246, doi:10.1037/10759-010, archived from the original on 2018-06-04, retrieved 2025-03-16
Jara, Elvia; Vila, Javier; Maldonado, Antonio (2006). "Second-Order Conditioning of Human Causal Learning". Learning and Motivation. 37 (3): 230–246. doi:10.1016/j.lmot.2005.12.001.
Murphy, Gardner (1947), "The Hierarchy of Conditionings.", Personality: A biosocial approach to origins and structure., New York: Harper & Brothers, pp. 224–246, doi:10.1037/10759-010, archived from the original on 2018-06-04, retrieved 2025-03-16