Plane trigonometry 
Barcelon, Dolores G...[et.al.]. 
 -  Trinitas Publishing, Inc.,  2003 
 - 228 pages 
<br/><br/>
<br/><br/><label>ISBN: </label>9-71420411-9 
<br/><br/><label>Dewey Class. No.: </label>F 516.24 P69 2003