Columbia subject headings:
Electric industries--Germany--History--20th century.
Energy industries--Germany--History--20th century.
Harvard subject headings:
Electric industries--Germany--History--20th century.
Energy industries--Germany--History--20th century.
Energy industries--Prices--Germany--History--20th century.
Energy policy--Germany--History--20th century.
Energy storage--Germany--History--20th century.
Power resources--Germany--History--20th century.
Princeton subject headings:
Electric industries--Germany--History--20th century.
Energy industries--Germany--History--20th century.
Energy industries--Prices--Germany--History--20th century.
Energy policy--Germany--History--20th century.
Energy storage--Germany--History--20th century.
Power resources--Germany--History--20th century.