Cochran  G.William <br/><br/>
Sampling techniques / 
William G.Cochran 
 - New York :  John Wiley & Sons, 
<br/><br/><br/>18 
<br/><br/> pbk 
<br/><br/><label>ISBN: </label>20 
<br/><br/><label>Dewey Class. No.: </label>COC-S STS. 75132