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
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
ca. 1952–1956 - Internal museum documents Publicity report for the exhibition Studies for Guernica by the University of Minnesota Gallery, addressed to the Travelling Exhibitions Department at the Museum of Modern Art, New York