Amsterdam, 23 May 1956 - Institutional correspondence Willem Sandberg's letter to Bo Wennberg, dated 23 May 1956
Stockholm, 7 June 1956 - Institutional correspondence Bo Wennberg's letter to Willem Sandberg, dated 7 June 1956
Stockholm, 6 May 1956 - Institutional correspondence Bo Wennberg's letter to Willem Sandberg, dated 6 May 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
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, 28 January 1957 - Institutional correspondence Willem Sandberg's letter to Bo Wennberg, dated 28 January 1957
