Columbia subject headings:
Harvard subject headings:
Electric power consumption--Germany--Hesse--History--Exhibitions.
Electric power systems--Germany--Hesse--History--Exhibitions.
Energy industries--Germany--Hesse--History--Exhibitions.
Energy policy--Germany--Hesse--History--Exhibitions.
Princeton subject headings:
Electric industries--Germany--Hesse--History--Pictorial works.
Electric industries--Germany--Hesse--History.