Columbia subject headings:
American drama--20th century--History and criticism.
O'Neill, Eugene, 1888-1953--Criticism and interpretation.
Harvard subject headings:
American drama--20th century--History and criticism
O'Neill, Eugene, 1888-1953--Criticism and interpretation.
Princeton subject headings:
American drama--20th century--History and criticism--Congresses.
O'Neill, Eugene, 1888-1953--Criticism and interpretation--Congresses.