TY  - BOOK
AU  - Piaget, Jean,
TI  - The child's conception of physical casuality
U1  - 155.4 
PY  - 1930///
CY  - London
PB  - K. Paul
KW  - Child study
N1  - Translated by Marjorie Gabain"; Half-title: International library of psychology, philosophy and scie ntific method
ER  -