Smith, T. Lynn. <br/><br/>
Demography :  principles and methods / 
T. Lynn Smith and Paul E. Zopf, Jr. 
 - Philadelphia :  Pennsylvania,  1970 
 - xv, 590 p. :  plates ;  24 cm. 
<br/><br/>Includes index. 
<br/><br/> Open access. 
<br/><br/><label>ISBN: </label>0803679203 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Demography.