Cambridge, Massachusetts, 20 November 1939 - Personal correspondence Josep Lluís Sert's letter to Pablo Picasso, dated 20 November 1939
Cambridge, Massachusetts, 8 December 1955 - Institutional correspondence Josep Lluís Sert's letter to Willem Sandberg
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
Cambridge, Massachusetts, 29 November 1980 - Institutional correspondence Josep Lluís Sert's letter to Dominique Bozo
Madrid, 31 July, and Cambridge, Massachusetts, 31 August 1981 - Institutional correspondence Álvaro Martínez Novillo's letter to Josep Lluís Sert, with reply
Cambridge (Massachusetts), 23 December 1976 - Institutional correspondence A letter from Josep Lluís Sert to Herschel B. Chipp
ca. 9 January 1939 - Personal correspondence Josep Lluís Sert's letter to Pablo Picasso, dated ca. 9 January 1939