AU  - Sethi,N.K..
ED  - Sethi                                                                                                                                                                                                                                                          .
TI  - Text-Book of Optics / 
U1  - 535.15 
PY  - 1965///
CY  - N.Delhi-1
PB  - Premier Publishing Co. , 
KW  - Physics
N1  - NULL
ER  -