TY  - BOOK
AU  - Nielsen and Vanlonkhuyzen
AU  - Nielsen and Vanlonkhuyzen
TI  - Plane and Spherical Trigonometry
U1  - 516 PLA 1946 
PY  - 1946///
CY  - New York
PB  - Noble Inc New York
N1  - Including Index; Functions of acute angles -- The general angles
ER  -