TY  - GEN
AU  - Jayasinghe ,  E.M. 
AU  - Jayarathna , Osmand 
TI  - Physics: geometrical optics block 2-B
U1  - 535.32 
PY  - 1984///
CY  - Nugegoda
PB  - Open University
KW  - OPTICS
KW  - PHYSICS
ER  -