Columbia subject headings:
Art, Abstract--Europe--Exhibitions.
Art, Abstract--United States--Exhibitions.
Art, American--20th century--Exhibitions.
Art, European--20th century--Exhibitions.
Harvard subject headings:
Art, Abstract--Europe--Exhibitions.
Art, Abstract--United States--Exhibitions
Art, Modern--20th century--Europe--Exhibitions.
Art, Modern--20th century--United States--Exhibitions.
Princeton subject headings: