Columbia subject headings:
Harvard subject headings:
Drama--Technique--History--20th century.
Dramaturges--History--20th century.
German drama--20th century--History and criticism.
Theater--Production and direction--History--20th century.
Princeton subject headings:
Drama--Technique--History--20th century.
Dramaturges--History--20th century.
German drama--20th century--History and criticism.
Theater--Production and direction--History--20th century.