Columbia subject headings:
Art, American--20th century.
Art, European--20th century.
Folk art--Europe.
Folk art--United States.
Outsider art--Europe.
Outsider art--United States.
Primitivism in art--Europe.
Primitivism in art--United States.
Harvard subject headings:
Art and society
Art and society--Congresses
Art brut--Congresses.
Art brut.
Art, Primitive--Congresses.
Art, Primitive.
Outsider art
Outsider art--Congresses.
Princeton subject headings:
Art and society.
Art brut.
Art.
Outsider art.