Langer, Jonas. <br/><br/>
The origins of log :    from six to twelve months / 
Jonas Langer. 
 - New York :    Academic Press,  1980. 
 - 437 p. :    ill. ;    24 cm. 
 - Developmental psychology series. .
<br/><br/>Bibliography : p . 433-434. 
<br/><br/><label>ISBN: </label>0124361501 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Cognition in children.<br/>Logic.<br/>Infant psychology.