Columbia subject headings:
Art, Modern--20th century--Periodicals--Bibliography.
Art--Periodicals--Bibliography.
Avant-garde (Aesthetics)--History--20th century--Periodicals--Bibliography.
Mail art--Periodicals--Bibliography.
Harvard subject headings:
Arts, Modern--20th century--Periodicals
Avant-garde (Aesthetics)--History--20th century--Periodicals.
Conceptual art--Periodicals.
Princeton subject headings: