Columbia subject headings:
Communism--Germany--History.
Communists--Germany--Biography.
Hippe, Oskar, 1900-
Harvard subject headings:
Communism--Germany--History
Communists--Germany--Biography
Hippe, Oskar, 1900-
Princeton subject headings:
Communism--Germany--History.
Communists--Germany--Biography.
Hippe, Oskar, 1900-