Piaget, Jean  <br/><br/>
The child's conception of number 

 - 1 ed. 
 - London :   Routledge  Kegan Paul Ltd,   c1941 
 - 248 p 
<br/><br/><label>Subjects--Topical Terms: </label><br/>educación<br/>aritmética
<br/><br/><label>Dewey Class. No.: </label>511.2000 P57