References
- Day , E. J. 1932 . Development of language in twins . Child Devel. , 3 : 179 – 199 .
- Freedman , D. G. and Keller , B. 1963 . Inheritance of behavior in infants . Science , 140 : 196 – 198 .
- Gesell , A. 1928 . Infancy and Human Growth , New York : Macmillan .
- Gesell , A. and Amatruda , C. 1941 . Development Diagnosis , New York : Harper .
- Jeans , P. C. , Wright , F. H. and Blake , F. G. 1958 . Essentials of Pediatrics , Philadelphia , Pa. : Lippincott .
- Jones , H. E. 1954 . “ The environment ” . In Manual of Child Psychology , Edited by: Carmichael , L. 631 – 696 . New York : Wiley .
- McCarthy , D. 1954 . “ Language development ” . In Manual of Child Psychology , Edited by: Carmichael , L. 492 – 630 . New York : Wiley .
- McGuire , C. and White , G. 1955 . “ The measurement of social status. Research paper ” . In Human Development No. 3 (rev.) , Austin , Texas : Univ. Texas .
- Shirley , M. M. 1933 . “ The first two years: A study of twenty-five babies ” . In Intellectual development. Inst. Child Welf. Monog , Vol. 2 , Minneapolis : University of Minnesota Press .