Amsterdam, 11 January 1956 - Transport documents Willem Sandberg's letter to Holland-Amerika Lijn, dated 11 January 1956
Amsterdam, 11 January 1956 - Institutional correspondence Willem Sandberg's letter to Robert Giron, dated 11 January 1956
Rotterdam, 13 January 1956 - Transport documents A letter from Holland-Amerika Lijnto to Willem Sandberg, dated 13 January 1956
Amsterdam, 21 February 1956 - Transport documents Willem Sandberg's letter to Holland-Amerika Lijn, dated 21 February 1956
Amsterdam, 25 February 1956 - Transport documents Willem Sandberg's letter to Holland-Amerika Lijn, dated 25 February 1956
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
Brussels, 7 May 1956 - Institutional correspondence Robert Giron's letter to Willem Sandberg, dated 7 May 1956
Stockholm, 1 October 1956 - Institutional correspondence Bo Wennberg's letter to Willem Sandberg, dated 1 October 1956 (copy)
Amsterdam, 27 February 1956 - Institutional correspondence Willem Sandberg's letter to Robert Giron, dated 27 February 1956
Brussels, 6 December 1956 - Institutional correspondence Robert Giron's letter to Willem Sandberg, dated 6 December 1956
Stockholm, 7 December 1956 - Institutional correspondence Bo Wennberg's letter to Willem Sandberg, dated 7 December 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
Rotterdam, 20 December 1956 - Transport documents A letter from Holland-Amerika Lijn to Willem Sandberg, dated 20 December 1956
Amsterdam, 21 December 1956 - Institutional correspondence Willem Sandberg's letter 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
Rotterdam, 1956 - Transport documents A contract from the transport company Holland-Amerika Lijn for the delivery of Guernica and studies to New York
