"Casley, D.J." <br/><br/>
Data collection in developing countries/ 
D.J. Casley 
 - 2nd ed. 
 - Oxford:  "Clarendon Press," 
<br/><br/><label>ISBN: </label>198772823 
<br/><br/><label>Dewey Class. No.: </label>1.4  / CAS