1. Signifikantz—Untersuchungen der Einfachen Strukter in der Factoren Analyse;Bargmann,1954
2. The Eight Mental Measurements Yearbook,1978
3. The Scree test for the number of factors;Cattell;Multivariate Behav. Res.,1966
4. The Scientific Use of Factor Analysis in Behavioural and Life Sciences;Cattell,1978
5. A comprehensive trial of the scree and KG criteria for determining the number of factors;Cattell;Multivariate Behav. Res.,1977