Amsterdam, 8 November 1955 - Institutional correspondence Willem Sandberg's letter to Josep Lluís Sert
Paris, 30 January 1964 - Institutional correspondence A letter from the Committee of the exhibition España Libre (Free Spain) to Pablo Picasso
Berlin, 1975 - Photograph View of the exhibition Kunst und Politik am Beispiel Guernica Picasso und der Spanische Bürgerkrieg
London, 6 November 1938 - Personal correspondence Roland Penrose's letter to Pablo Picasso, dated 6 November 1938
Mexico, 21 December 1939 - Personal correspondence Juan Larrea's letter to Pablo Picasso, dated 21 December 1939