Piaget, Jean,  1896-1980. <br/><br/>
Possibility and necessity / 
Jean Piaget ; with E. Ackermann-Valladao ... [et al.] ; translated from the French by Helga Feider. 
 - Minneapolis :  University of Minnesota Press,  c1987. 
 - 2 v. :  ill. ;  24 cm. 
<br/><br/> Translation of: Le possible et le neÃÅcessaire. 
<br/><br/>Includes bibliographical references and indexes. 
<br/><br/>v. 1. The role of possibility in cognitive development -- v. 2. The role of necessity in cognitive development. 
<br/><br/><label>ISBN: </label>0816613702 (v. 1) 0816613729 (v. 2) 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Possibility--Psychological aspects.<br/>Necessity (Philosophy)<br/>Reality in children.<br/>Cognition in children.