Lovell, K.  <br/><br/>
The growth of basic mathematical and scientific concepts in children /  
by K. Lovell. 
 - 5th ed., 2nd impression. 
 - London :    University of London Press,    1968. 
 - 158 p. :    ill. ;    22 cm. 
 - Unibooks .
<br/><br/>Includes bibliographical references 
<br/><br/><label>Subjects--Topical Terms: </label><br/> Number concept in children.<br/> Conservation (Psychology).
<br/><br/><label>Dewey Class. No.: </label>372.7019