TY  - GEN
AU  - Jayasinghe , E.M.
AU  - Jayasinghe , E.M. 
AU  - Osmund , Jayaratne
TI  - Physics : geometrical optics block 2 B
U1  - 535.32 
PY  - 1984///
CY  - Nugegoda
PB  - Open University
KW  - Physical Optics
KW  - Physics
ER  -