1. Wechsler, D.: The Measurement of Adult Intelligence. (2nd edition.) Williams and Wilkins Co. Baltimore. 1941.
2. Kendig, I., and Richmond, W. V.: Psychological Studies in Dementia Præcox. pp. 1–211. Edwards Bros. Ann Arbor. 1940.
3. Rapaport, D.: Recent developments in clinical psychology. Trans. Kan. Acad. of Sci., 42:290–292, 1942.
4. Roe, A., and Shakow, D.: Intelligence in Mental Disorder. Pp. 361–490. Annals N. Y. Acad. of Sci. New York. 1942.
5. Trapp, E. E., and James, E. B.: Comparative intelligence ratings in the four types of dementia præcox. J. N. M. D., 86:399–404, 1937.