Columbia subject headings:
O'Neill, Eugene, 1888-1953--Miscellanea.
Harvard subject headings:
Drama--History and criticism--Theory, etc.
Dramatists, American--20th century--Correspondence.
O'Neill, Eugene, 1888-1953--Correspondence.
O'Neill, Eugene, 1888-1953--Knowledge--Performing arts.
O'Neill, Eugene, 1888-1953--Quotations.
Princeton subject headings:
O'Neill, Eugene, 1888-1953--Miscellanea.