Ecological relationships / 
N. Gilbert ...[et al.] 
 - San Francisco :  W. H. Freeman,  1976 
 - 154 p. :  ill. ;  22 cm. 
<br/><br/>Bibl.: p.149-154. - Index 
<br/><br/><label>ISBN: </label>0716704862 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Population biology