Levins, Richard. <br/><br/>
Evolution in changing environments :  some theoretical explorations / 
[by] Richard Levins. 
 - Princeton, N.J. :  Princeton University Press,  1968. 
 - ix, 120 p. :  ill. ;  22 cm. 
 - Monographs in population biology .
<br/><br/> Includes index. 
<br/><br/><label>LCCN: </label>68-20871 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Population biology.