Columbia subject headings:
American drama--20th century--History and criticism.
English drama--20th century--History and criticism.
Verse drama, American--History and criticism.
Verse drama, English--History and criticism.
Harvard subject headings:
American drama--20th century--History and criticism
English drama--20th century--History and criticism
Verse drama, American--History and criticism.
Verse drama, English--History and criticism.
Princeton subject headings:
American drama--20th century--History and criticism.
English drama--20th century--History and criticism.
Verse drama, American--History and criticism.
Verse drama, English--History and criticism.