Paris, 29 September 1955 - Institutional correspondence Daniel-Henry Kahnweiler's letter to Willem Sandberg, dated 29 September 1955
Amsterdam, 8 November 1955 - Institutional correspondence Willem Sandberg's letter to Josep Lluís Sert
Roxbury, 22 November 1955 - Institutional correspondence Alexander Calder's letter to Willem Sandberg, dated 22 November 1955
Cambridge, Massachusetts, 8 December 1955 - Institutional correspondence Josep Lluís Sert's letter to Willem Sandberg
Amsterdam, 21 December 1956 - Institutional correspondence Willem Sandberg's letter to Alfred H. Barr Jr.
Rotterdam, 1956 - Transport documents A contract from the transport company Holland-Amerika Lijn for the delivery of Guernica and studies to New York
Rotterdam, 1956 - Transport documents A packing list for the delivery of 6 boxes with Guernica and studies from Amsterdam to New York
Amsterdam, 25 January 1956 - Transport documents M. Winter's letter to Robert Giron, dated 25 January 1956
Brussels, 17 February 1956 - Institutional correspondence Robert Giron's letter to Willem Sandberg, dated 17 February 1956
Brussels, 25 February 1956 - Institutional correspondence Robert Giron's letter to Willem Sandberg, dated 25 February 1956
Amsterdam, 16 January 1957 - Institutional correspondence A telegram from Willem Sandberg to Alfred H. Barr Jr.
New York, 23 January 1957 - Transport documents A letter from the vice-president of W. R. Keating & Company to Willem Sandberg
Amsterdam, 28 January 1957 - Institutional correspondence Willem Sandberg's letter to Robert Giron, dated 28 January 1957
Amsterdam, 28 January 1957 - Institutional correspondence Willem Sandberg's letter to Bo Wennberg, dated 28 January 1957