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
New York, 3 December 1957 - Internal museum documents A letter from Dorothy C. Miller to Monroe Wheeler
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
New York, 9 September 1939 - Institutional correspondence John Sherman's letter to Marcelene Peterson
New York, 3 May 1968 - Institutional correspondence Dorothy C. Miller's letter to Daniel-Henry Kahnweiler
New York, 21 February 1966 - Management of reproduction rights Dorothy C. Miller's letter to Pearl Moeller