Stockholm, 7 June 1956 - Institutional correspondence Bo Wennberg's letter to Willem Sandberg, dated 7 June 1956
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
Stockholm, 6 May 1956 - Institutional correspondence Bo Wennberg's letter to Willem Sandberg, dated 6 May 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
Stockholm, 10 October 1956 - Institutional correspondence Bo Wennberg's letter to Willem Sandberg, dated 10 October 1956
Stockholm, 1 October 1956 - Institutional correspondence Bo Wennberg's letter to Willem Sandberg, dated 1 October 1956 (copy)
Stockholm, 7 December 1956 - Institutional correspondence Bo Wennberg's letter to Willem Sandberg, dated 7 December 1956
Hollywood, 20 July 1939 - Institutional correspondence Marcelene Peterson's letter to Evelyn Ahrend, dated 20 July 1939
Hollywood, 2 September 1939 - Institutional correspondence Marcelene Peterson's letter to Evelyn Ahrend, dated 2 September 1939
Hollywood, 10 November 1939 - Institutional correspondence Marcelene Peterson's letter to Herman F. Reissig