Ginsburg, Herbert P. <br/><br/>
Piaget's theory of intellectual development / 
Herbert P. Ginsburg & Sylvia Opper 
 - 3rd ed. 
 - Englewood Cliffs, N. J. :  Prentice-Hall,  1988 
 - viii, 264 p. ;  24 cm. 
<br/><br/>p. 257-261 
<br/><br/><label>ISBN: </label>0136751660 
<br/><br/><label>LCCN: </label>87-17353 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Cognition in children<br/>Intellect<br/>Education--Philosophy