Keyfitz, Nathan,  1913- <br/><br/>
Demography through problems / 
Nathan Keyfitz, John A. Beekman 
 - New York :  Springer-Verlag,  1984 
 - 141 p. ;  27 cm. 
 - Problem books in mathematics .
<br/><br/>Bibliography : p.135-136 
<br/><br/><label>ISBN: </label>0387908366 
<br/><br/><label>LCCN: </label>83-6775 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Demography--Problems, exercises, etc