Columbia subject headings:
German drama--20th century--History and criticism.
Soviet Union--History--Revolution, 1917-1921--Influence.
Harvard subject headings:
German drama--20th century.
Soviet Union--History--Revolution, 1917-1921--Literature and the revolution.
Princeton subject headings:
German drama--20th century--History and criticism.
Soviet Union--History--Revolution, 1917-1921--Literature and the revolution.