Amsterdam, 17 October 1956 - Institutional correspondence A letter from Hans Ludwig Cohn Jaffé's to the editors of the newspaper De Tijd
Stockholm, 11 September 1956 - Institutional correspondence Bo Wennberg's letter to the Stedelijk Museum
Stockholm, 23 October 1956 - Institutional correspondence A letter from Bo Wennberg and K. G. Hulten to Pablo Picasso
New York, 27 November 1956 - Institutional correspondence Bernard Karpel's letter to Willem Sandberg, dated 27 November 1956
Amsterdam, 6 December 1956 - Institutional correspondence Willem Sandberg's letter to Bernard Karpel, dated 6 December 1956
Stockholm, 6 May 1956 - Institutional correspondence Bo Wennberg's letter to Willem Sandberg, dated 6 May 1956
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
Amsterdam, 15 September 1956 - Institutional correspondence Willem Sandberg's letter to Bo Wennberg, dated 15 September 1956
Stockholm, 20 September 1956 - Institutional correspondence Bo Wennberg's letter to Willem Sandberg, dated 20 September 1956
Amsterdam, 24 September 1956 - Institutional correspondence Willem Sandberg's letter to Bo Wennberg, dated 24 September 1956
Stockholm, 1 October 1956 - Institutional correspondence Bo Wennberg's letter to Willem Sandberg, dated 1 October 1956
Amsterdam, 9 October 1956 - Institutional correspondence Willem Sandberg's letter to Bo Wennberg, dated 9 October 1956
Stockholm, 10 October 1956 - Institutional correspondence Bo Wennberg's letter to Willem Sandberg, dated 10 October 1956
Amsterdam, 15 October 1956 - Institutional correspondence Willem Sandberg's letter to Bo Wennberg, dated 15 October 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