TY  - BOOK
AU  - Lovell,Kenneth
TI  - The growth of basic mathematical and scientific concepts in children,
SN  - NA
U1  - 136.7 
PY  - 1962///, c1961]
CY  - New York
PB  - Philosophical Library
KW  - Number concept
KW  - Conservation (Psychology)	
KW  - Number concept in children
N1  - Includes bibliographies
ER  -