Pearson, Helen R <br/><br/>
Trigonometry and related topics 
/ Helen R. Pearson 
 - Boston  Ginn and Company  1971 
 - ix, 390 p. : ill. ; 24 cm. 
<br/><br/> Includes index. 
<br/><br/><label>ISBN: </label>0663212189 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Trigonometry