28 February 1974 - Press release and communication The artist Tony Shafrazi has freed Guernica from its chains of ownership and has returned its revolutionary nature
Horseheads, New York, 23 January 1956 - Management of reproduction rights Hugh Thomas's letter to Alfred H. Barr Jr.
New York: Praeger Publishers Inc., 1973 - Essay Six Years: The Dematerialization of the Art Object from 1966 to 1972