TY  - BOOK
AU  - Piaget,Jean
TI  - The child's conception of number
AV  - BF723.N8 P53
U1  - 136.745101 
PY  - 1964///]
CY  - London
PB  - Routledge & Paul
KW  - Child psychology
KW  - Local
KW  - Number concept
ER  -