Columbia subject headings:
English drama--20th century--History and criticism--Congresses.
Stage adaptations--History and criticism--Congresses.
Harvard subject headings:
English drama--20th century--History and criticism--Congresses.
Stage adaptations--History and criticism--Congresses.
Princeton subject headings:
English drama--20th century--History and criticism--Congresses.
Stage adaptations--History and criticism--Congresses.