TY  - GEN
AU  - Gunasinghe , R.M.
AU  - Nanda , D.M. ;ed. ; Liyanage , L.S.G.
TI  - Physics geometrical optics : founndation science
U1  - 535.32 
PY  - 1986///
CY  - Nugegoda
PB  - Open University
KW  - PHYSICS
KW  - OPTICS
ER  -