The ESSENTIAL piaget 
/edited by Howard E. Gruber, J.Jacques Voneche 
 - London  Routledge & Kegan Paul  1977 
 - xlii, 881 p. 
<br/><br/> Includes bibliography & index. 
<br/><br/><label>ISBN: </label>071009213X 
<br/><br/><label>Dewey Class. No.: </label>155.4  / ESS