Old Westbury, New York, 4 May 1977 - Institutional correspondence Emilia Doyaga's letter to Nelson Rockefeller
Madrid, 22 September 1936 - Institutional correspondence Francisco Sánchez Cantón's telegram to Pablo Picasso
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