Verlag SiemensErich Gelder × The Transistor Erich GelderSiemensSoftcover1988 The Transistor as a Switch Erich GelderSiemensSoftcover1988 The Transistor as AF-AmplifierPrestagesErich GelderSiemensSoftcover1988 The Transistor as AF-AmplifierOutput StagesErich GelderSiemensSoftcover