TY  - GEN
AU  - Gunasinghe , R. M.
AU  - Liyanage ,  L. S. G. 
AU  - Tennakoone, M. M. S. G .K
AU  - Dahanayaka, C.
TI  - Physics: geometrical optics
U1  - 535.32 
PY  - 1986///
CY  - Nugegoda
PB  - Open university of  Sri Lanka
KW  - PHYSICS
KW  - GEOMETRICAL OPTICS
KW  - REFLECTION
KW  - REFRACTION
ER  -