TY  - BOOK
TI  - Plane & spherical trigonometry: a tetrahedron approach 
SN  - 9789719654056
U1  - Fil 516 P712 2015 
PY  - 2015///
CY  - Manila
PB  - Unlimited Books Library Services & Publishing Inc.
N1  - includes appendix, index, references
ER  -