Nomenclature des stations de radiodiffusion = List of broadcasting stations = Nomenclátor de las estaciones de radiodifusión Principles of aeronautical radio engineering / by P.C. Sandretto Voorlopige noodregeling verbindingsdienst ten behoeve van de civiele verdediging Introduktie tot de militaire geheimtelecommunicatie- systemen / door E. Mahler Radio engineering / by Frederick Emmons Terman Measurements in radio engineering / by Frederick Emmons Terman Communication engineering / by William Littell Everitt