00463nam a2200145Ia 4500003000900000008004100009040001600050080002200066245009500088260003500183300002300218650004100241650002400282650001100306IN-BaIIA211028s9999    xx            000 0 eng d  cIIA Library  a535.8(082.1)bOPT 0aOptical instruments 1950bproceedings of the London Conference on Optical Instruments 1950  aLondonbChapman and Hallc1951  a[various pagings.]  aAstronomy and astrophysics thesaurus  aOptical instruments  aOptics