Friis Robert H <br/><br/>
Epidemiology for public health practice 
Friis Robert H; Sellers Thomas A 
 - 2th 
 - U  U, S A Aspen  1999 
 - xiv,506 
<br/><br/><label>ISBN: </label>0-8342-1178-5 
<br/><br/><label>Source: </label>Textbook