The essential piaget / 
Edited byHoward E. Gruber. 
 - New York :  Basic books,  c1977. 
 - 881p. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Cognition.<br/>Knowledge.
<br/><br/><label>LC Class. No.: </label>BF723  / .C5  / P494