New York, 12 March 1956 - Institutional correspondence Bernard Karpel's letter to Willem Sandberg, dated 12 March 1956
Amsterdam, 19 March 1956 - Institutional correspondence Willem Sandberg's letter to René d'Harnoncourt
Amsterdam, 19 March 1956 - Institutional correspondence Willem Sandberg's letter to the Valentin Gallery
Brussels, 4 April 1956 - Institutional correspondence Robert Giron's letter to Willem Sandberg, dated 4 April 1956
Rotterdam, 4 April 1956 - Transport documents A letter from Holland-Amerika Lijn to Willem Sandberg, dated 4 April 1956
Amsterdam, 4 May 1956 - Institutional correspondence Willem Sandberg's letter to Robert Giron, dated 4 May 1956
Paris, 22 May 1956 - Institutional correspondence Daniel-Henry Kahnweiler's letter to Willem Sandberg, dated 22 May 1956
Amsterdam, 22 May 1956 - Institutional correspondence Willem Sandberg's letter to Pablo Picasso, dated 22 May 1956
Amsterdam, 23 May 1956 - Institutional correspondence Willem Sandberg's letter to Bo Wennberg, dated 23 May 1956
Amsterdam, 23 May 1956 - Institutional correspondence Willem Sandberg's letter to Daniel-Henry Kahnweiler, dated 23 May 1956
Stockholm, 7 June 1956 - Institutional correspondence Bo Wennberg's letter to Willem Sandberg, dated 7 June 1956
Amsterdam, 19 July 1956 - Internal museum documents Willem Sandberg's letter to Amsterdam City Council, dated 19 July 1956
Amsterdam, 17 October 1956 - Institutional correspondence A letter from Hans Ludwig Cohn Jaffé's to the editors of the newspaper De Tijd
Brussels, 7 May 1956 - Institutional correspondence Robert Giron's letter to Willem Sandberg, dated 7 May 1956
19 July 1956 - Personal correspondence Daniel-Henry Kahnweiler's letter to Pablo Picasso, dated 19 July 1956
Rotterdam, 1956 - Transport documents A packing list for the delivery of 6 boxes with Guernica and studies from Amsterdam to New York
Amsterdam, 6 July 1956 - Institutional correspondence A letter from J. M. Trias de Bes to Alberto Martín-Artajo Álvarez
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
Rotterdam, 1956 - Transport documents A contract from the transport company Holland-Amerika Lijn for the delivery of Guernica and studies to New York