Creswell, John W. <br/><br/>
Designing and conducting mixed methods research 
John W. Creswell, Vicki L. Plano Clark 
 - 2nd. ed. 
 - Los Angeles  Sage Pub.  2011 
 - xxvi, 457p.;  ill.  24cm. 
<br/><br/> includes index :p.433 - 457 
<br/><br/><label>ISBN: </label>9780412975179 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Research--evaluation<br/>Social sciences--research--methodology