000 00278nam a2200121Ia 4500
008 170101s1948 xx 000 0 und d
082 _a621.381 51 S63V
100 _aSPANGENBERG, K.R
245 0 _aVacuum tubes
260 _bN.Y.
_c1948
300 _axvii,860p
942 _2ddc
_cB
999 _c13658
_d13658