Primer of Epidemiology / 
Friedman D. Gary. 
 - 5th ed. 
 - New York :  McGraw- Hill,  c 2004. 
 - x, 401 p. : 
<br/><br/> Includes Index 
<br/><br/><label>ISBN: </label>0071402586 
<br/><br/><label>LC Class. No.: </label>RA 651  /  .F68