Nielsen, Kaj Leo, 1914- <br/><br/>
Plane and spherical trigonometry / 
by Kaj l. Nielsen and John H. Vanlonkhuyzen. 
 - New York :  Barnes  and Nobles,  [1966] 
 - xv, 139 p. illus tables 21 cm 
 - College outline series, no. 45 .
<br/><br/> Includes bibliographical references 
<br/><br/><label>LC Class. No.: </label>514.5  / N554