Columbia subject headings:
Harvard subject headings:
Art, Modern--20th century--Themes, motives
Avant-garde (Aesthetics)--History--20th century.
Happenings (Art)
Performance art
Princeton subject headings:
Art, Modern--20th century--Themes, motives.
Avant-garde (Aesthetics)--History--20th century.
Happenings (Art)
Performance art.