DROOYAN, Irving <br/><br/>
Essentials of Trigonometry 

 - 2nd Ed. 
 - New York.  Macmillan Pub , US  1977 
 - viii, 328p 
<br/><br/><label>ISBN: </label>23302208 
<br/><br/><label>Dewey Class. No.: </label>516.24