Parker, Bertha Morris. <br/><br/>
Balance in nature / 
Bertha Morris Parker and Ralph Buchsbaum. 
 - Illinois :  Row Peterson,  1955. 
 - 35 p.282 p. ;  22 cm. 
 - Basic Science Education Series .
<br/><br/><label>ISBN: </label>(N.A.) :  (N.A.) 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Natural history.<br/>Environmental sciences.<br/>Science.
<br/><br/><label>Dewey Class. No.: </label>T 508