Columbia subject headings:
Germany--History--1918-1933.
Musical theater--Germany--Bochum--20th century.
Musical theater--Germany--Hannover--20th century.
Harvard subject headings:
Germany--History--1918-1933.
Music and state.
Music--Germany--20th century--History and criticism
Musical theater--Germany--Bochum--History--20th century.
Musical theater--Germany--Hannover--History--20th century.
Princeton subject headings:
Opera--Germany--Bochum--20th century.
Opera--Germany--Hannover--20th century.