1. Altus, W. Sibling order and scholastic aptitude. Amer. Psychol, 1962, 17, 304. (Abstract)
2. Berdie, R., Dressel, P., & Kelso, P. Relative validity of the Q and L scores of the ACE Psychological Examination. Educ. psychol Measmt., 1951, 11, 803–812.
3. Hsiao, H. H. The status of the first born with specific reference to intelligence. Genetic Psychol. Monogr., 1931, 9, 1–118.
4. Koch, Helen. The relation of “Primary Mental Abilities” in five- and six-year olds to sex of child and characteristics of his sibling. Child Developm., 1954, 25, 209–223.
5. Lynn, D. B. Sex-role and parental identification. Child Developm., 1962, 33, 555–564.