Beyer, Hugh. <br/><br/>
Contextual design :  defining customer-centered systems / 
Hugh Beyer and Karen Holtzblatt. 
 - San Francisco :  Morgan Kaufmann,  c1998. 
 - xxiii, 472 p. :  ill. ;  24 cm. 
<br/><br/> Includes index. 
<br/><br/>Includes bibliographical references. 
<br/><br/><label>ISBN: </label>1558604111 (pbk.) 
<br/><br/><label>Subjects--Topical Terms: </label><br/>System design.<br/>System analysis.