Columbia subject headings:
Harvard subject headings:
Clock and watch industry--Germany--History--20th century.
Clock and watch makers--Germany--History--20th century.
Kienzle Uhrenfabriken GmbH--History.
Mannesmann Kienzle GmbH--History.
Princeton subject headings:
Clock and watch industry--Germany--History--20th century.
Clock and watch makers--Germany--History--20th century.