Gulliksen, H.Theory of Mental Tests. New York: John Wiley and Sons, 1950 , pp. 380-385.
2.
Guttman, Louis.Supplementary Study B-4 in Horst, A. P. The Prediction of Personal Adjustment. New York: Social Science Research Council, Bulletin 48, 1941.
3.
Myers, R. C. and Schultz, D. G. "Predicting Academic Achievement with a New Attitude-Interest Questionnaire—I." EDUCATIONAL AND PSYCHOLOGICAL MEASUREMENT, X (1950 ), 654-663.