Lovell, K. <br/><br/>
The growth of basic mathematical and scientific concepts in children / 
by K. Lovell ; foreword by Barbel Inhelder. 
 - 5th ed. 
 - London:   University of London Press,   1972.  
 - 158 p. ;  21 cm. 
<br/><br/>Includes bibliographical refences and index. 
<br/><br/><label>ISBN: </label>0340083816 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Conservation (Psychology)<br/>Number concept in children
<br/><br/><label>Dewey Class. No.: </label>155.413