TY  - BOOK
ED  -  Ontario. Institute for Studies in Education. Educational Research se ries, No.2.
TI  -  Recent research on the acquisition of conservation of substance. Rep ort of papers from a seminar held in connection with the Conference on Preschool Education, Ontorio Institute of Education, November 15-17, 19 66: 
U1  -  AF 372.2108 ONT 
PY  - 1967///
CY  -  Toronto : 
PB  -  Ontorio Institute for Studies in Education, 
ER  -