1. The ability of science students to make conclusions
2. Statistics in Psychology and Education. New York: Longmans, Green and Company, 1940, pp. 226–229.
3. Statistics in Psychology and Education. New York: Longmans, Green and Company, “The Arrangement of Test Items into a Scale in which the Difficulty of Each Item is Known with Reference to an Arbitrary Zero Point.”Pp. 143–149.
4. Statistics in Psychology and Education. New York: Longmans, Green and Company, P. 319.