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:  
edited by David W. Brison and Edmund V. Sullivan. 
 - Toronto :    Ontorio Institute for Studies in Education,    1967. 
 - 71 p. 
 - Educational Research series ;    no.2. .
<br/><br/><label>Dewey Class. No.: </label>AF 372.2108 ONT