LITTERATUR
- Bloom , L. 1973 . One word at a time. The Hague : Mouton .
- Bower , T. G.R. 1967 . The development of object permanence: some studies of object constancy. . Perception and Psychophysics , 2 : 411 – 18 .
- Corrigan , R. A. 1978 . Language development as related to stage 6 object permanence development. . Journal of Child Language , 5 : 173 – 189 .
- Dore , J. 1975 . Holophrases, speech acts and language universals. . Journal of Child Language , 2 : 21 – 40 .
- Halliday , M. A.K. 1975 . Learning How to Mean: explorations in the development of language. London : Edward Arnold .
- McShane , J. 1979 . The development of naming. . Linguistics , 17 : 879 – 905 .
- Piaget , J. 1951 . Play, dreams and imitation in childhood. London : Routledge & Kegan Paul . (1945)
- Plunkett , K. 1985 . Projekt Barnesprog. . Nordisk Psykologi , 37 ( 1 )
- Tomasello , M. and Farrar , M. J. 1984 . Cognitive bases of lexical development: object permanence and relational words . Journal of Child Language , 11 : 477 – 493 .
- Uzgiris , I. C. and Hunt , J. McV. 1975 . Assessment in Infancy. Chicago : University of Illinois Press .