000 00261nam a2200109Ia 4500
008 160710s1948 xx 000 0 und d
100 _aSPANGENBERG
245 _aVACUUM TUBES
260 _aNEW YORK
_bMCGRAW HILL BOOK CO.
_c1948
300 _a860
942 _2ddc
_cB
999 _c25286
_d25286