Helton, Floyd Franklin,  1912 <br/><br/>
Analytic trigonometry 
by Floyd F. Helton. 
 - Philadelphia:  Saunders,  1972. 
 - vii, 297 p.  illus.  26 cm. 
<br/><br/><label>ISBN: </label>0721646328 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Plane trigonometry.
<br/><br/><label>Dewey Class. No.: </label>516.34 HEL