Plane and spherical trigonometry with applications 
Hart, William. 
 -  D.C Heath and Company.  1943 
 - 124 pages. 
<br/><br/>
<br/><br/><label>ISBN: </label>9-71081916-X 
<br/><br/><label>Dewey Class. No.: </label>516.24 H25p 1964