Amsterdam, 15 October 1956 - Institutional correspondence Willem Sandberg's letter to Bo Wennberg, dated 15 October 1956
Amsterdam, 27 February 1956 - Institutional correspondence Willem Sandberg's letter to Robert Giron, dated 27 February 1956
Amsterdam, 10 December 1956 - Institutional correspondence Willem Sandberg's letter to Robert Giron, dated 10 December 1956
Amsterdam, 20 December 1956 - Transport documents A letter from Willem Sandberg to Holland-Amerika Lijn, dated 20 December 1956
Amsterdam, 21 December 1956 - Institutional correspondence Willem Sandberg's letter to Alfred H. Barr Jr.
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
Amsterdam, 18 April 1956 - Press release and communication Picasso's Guernica and studies will be at the Stedelijk Museum from mid-July to the end of September