Yin, Robert K. <br/><br/>
Survey Research methods. 

 - 4th ed. 
 - USA :  Sage Publications, Inc,  2009. 
 - x, 201 p. :  ill. ;  22 cm. 
<br/><br/>Includes bibliographical references and index. 
<br/><br/><label>ISBN: </label>9781412958417 
<br/><br/><label>Dewey Class. No.: </label>001.42 YIN