00242nam a2200109Ia 4500008004100000041000800041082002800049100001000077245002800087260000900115300000800124211209s1974    xx            000 0 und d  aeng  a621.381 535 N74 SEE/SAM  aSEELY  aELECTRON-TUBE CIRCUITS   c1974  a695