Larson, Ron <br/><br/>
Trigonometry :  a graphing approach / 
Ron Larson. 
 - 4th ed. 
<br/><br/><label>ISBN: </label>0618317953 
<br/><br/><label>LCCN: </label>2003113995 
<br/><br/><label>LC Class. No.: </label>QA531