Columbia subject headings:
Harvard subject headings:
Businessmen--Germany--Darmstadt--Biography.
Businesspeople--Germany--Darmstadt--Biography.
College teachers--Germany--Darmstadt--Biography.
Darmstadt (Germany)--Biography.
Electrical engineering--Germany--Berlin--History.
Petersen, Waldemar, 1880-1946.
Princeton subject headings:
Businessmen--Germany--Darmstadt--Biography.
Businesspeople--Germany--Darmstadt--Biography.
College teachers--Germany--Darmstadt--Biography.
Electrical engineering--Germany--Berlin--History.
Petersen, Waldemar, 1880-1946.