Columbia subject headings:
Harvard subject headings:
Drees & Co. GmbH (Werl, Germany)--History.
Hydraulic machinery industry--Germany--Werl--History--19th century.
Hydraulic machinery industry--Germany--Werl--History--20th century.
Hydraulic turbines--Germany--Werl--History.
Iron foundries--Germany--Werl--History.
Turbines--Germany--Werl--History.
Werl (Germany)--Economic conditions.
Princeton subject headings:
Drees & Co. GmbH (Werl, Germany)--History.
Hydraulic machinery industry--Germany--Werl--History--19th century.
Hydraulic machinery industry--Germany--Werl--History--20th century.
Hydraulic turbines--Germany--Werl--History.
Iron foundries--Germany--Werl--History.
Turbines--Germany--Werl--History.
Werl (Germany)--Economic conditions.