Ausubel, D.Educational psychology: A cognitive view.New York: Holt, 1968.
2.
Dunn, J. A.School anxiety and cognitive functioning: Exploratory studies.Ann Arbor, Mich.: Interprofessional Research Commission on Pupil Personnel Services (IRCOPPS). Midwest Research Center for Pupil Personnel Services, 1967.
3.
Klein, N. K.Acquisition and retention of classification skills in trainable mentally retarded children.Cleveland: Case Western Reserve University, 1973.
4.
Piaget, J.The psychology of intelligence.Patterson, N.J.: Littlefield, Adams, 1960.
5.
Safford, P. L.Differences in cognitive functioning: Implications for school-relevant differential diagnosis.Ann Arbor, Mich.: Interprofessional Research Commission on Pupil Personnel Services (IRCOPPS). Midwest Research Center for Pupil Personnel Services, 1967.
6.
Sigel, I., McBane, B.Cognitive competence and level of symbolization among five-year old children. In J. Hellmuth (Ed.), The disadvantaged child (Vol. 1). Seattle: Special Child Publications, 1967.
7.
Zeaman, D., House, B. J.The role of attention in retardate discrimination learning. In N. Ellis (Ed.), Handbook of mental deficiency: Psychological theory and research. New York: McGraw-Hill, 1963.