Elementary survey sampling 
SCHEAFFER, Richard L   et.al. 
 - 6th ed. 
 -  Thomson Brooks/Cole  2006 
 - 464 p.  ill. 
<br/><br/><label>Subjects--Index Terms: </label>Survey sampling;  Sampling 
<br/><br/><label>Dewey Class. No.: </label>300.72