1. Guyer, M. F. 1942.Speaking of Man261New York
2. Lannert, Violet A. 1946. “Effects of Abstractness, Previous Knowledge, and Attitude on Reasoning”. Northwestern University. Unpublished dissertation
3. Lippitt, Ronald. 1949.Training in Community Relations79New York
4. Dewey, John. 1933.How We Think108–9. New York
5. Bacon, Francis. 1825.The Advancement of Learning39London