1. Cronbach, L. J. in Tagiuri, R. and Petrullo, L. (Ed.) Person Perception and Interpersonal Behavior (California: Stanford University Press, 1958), p. 362.
2. Social perception and teacher-pupil relationships.
3. Harris, C. W. (Ed.) Encyclopedia of Educational Research (New York: The McMillan Company, 1960), pp. 941–45.