Schaaf, William L. <br/><br/>
Trigonometry  : for home study 
William L. Schaaf 
 - Philadelphia  New home library  1945 
 - 403p. 
<br/><br/> Includes index 
<br/><br/><label>ISBN: </label>
<br/><br/><label>Subjects--Topical Terms: </label><br/>Mathematics
<br/><br/><label>Dewey Class. No.: </label>516.24  / SCH291