000 00273nam a22001217a 4500
020 _a978-8183561136
022 _a8183561136
100 _a R.K. Verma
245 _aRay Optics
260 _aNEW DELHI
_bDISCOVERY PUBLISHING HOUSE
_c2020
300 _a341 PAGES
942 _cBK
999 _c4605
_d4605