New York, 9 July 1956 - Institutional correspondence Alfred H. Barr Jr.'s letter to Pablo Picasso, dated 9 July 1956
New York, 20 February 1956 - Institutional correspondence Alfred H. Barr Jr.'s letter to Nelson Rockefeller
New York, 31 March 1956 - Institutional correspondence Alfred H. Barr Jr.'s letter to Pablo Picasso, dated 31 March 1956
New York, 12 May 1956 - Institutional correspondence Alfred H. Barr Jr.'s letter to Pablo Picasso, dated 12 May 1956
New York, 10 February 1956 - Institutional correspondence A letter from Alfred H. Barr Jr. to Petro (Nelly) Van Doesburg, dated 10 February 1956
New York, 20 February 1956 - Institutional correspondence Alfred H. Barr Jr.'s letter to Petro (Nelly) Van Doesburg, dated 20 February 1956
New York, 21 November 1956 - Institutional correspondence Alfred H. Barr Jr.'s letter to Lars Rostrup Boyesen
Stockholm, 1956 - Photograph Photographs of the installation and exhibition of Guernica, avec 60 études at the Nationalmuseum, Stockholm
October - December 1956 - Photograph Photograph of the installation of the exhibition Guernica, avec 60 études at the Nationalmuseum, Stockholm
New York, 27 February 1956 - Institutional correspondence Alfred H. Barr Jr.'s letter to Daniel-Henry Kahnweiler, dated 27 February 1956