Columbia subject headings:
Harvard subject headings:
Drama--20th century--History and criticism
Polgar, Alfred, 1873-1955--Criticism and interpretation.
Theater--History--20th century.
Theater--Technique.
Princeton subject headings:
Drama--20th century--History and criticism.
Polgar, Alfred, 1873-1955--Criticism and interpretation.
Theater--History--20th century.
Theater--Technique.