TY  - BOOK
AU  - Helmore,G.A.
TI  - Piaget: a practical consideration 
SN  - 0080068936
PY  - 1969///
CY  - Oxford
PB  - Pergamon Press
KW  - Piaget, Jean,
KW  - Child psychology
KW  - Geometry concept
N1  - 'Books and articles about Jean Piaget and his work: p. 69-72 and p. 73
ER  -