Columbia subject headings:
Harvard subject headings:
Electric power systems--Germany--North Rhine-Westphalia--History.
Rheinisch-Westfälisches Elektrizitätswerk Aktiengesellschaft--History.
Princeton subject headings:
Electric power systems--Germany--North Rhine-Westphalia--History.
Rheinisch-Westfälisches Elektrizitätswerk Aktiengesellschaft--History.