Columbia subject headings:
Drama--Technique--Congresses.
Theater and society--Congresses.
Theater--Philosophy--Congresses.
Harvard subject headings:
Drama--Technique--Congresses.
Theater and society--Congresses.
Theater--Philosophy--Congresses.
Princeton subject headings:
Drama--Technique--Congresses.
Theater and society--Congresses.
Theater--Philosophy--Congresses.