Flushing, New York, 23 May 1939 - Institutional correspondence Simon Guggenheim's and Dana C. Backus's form letter to ask for donations
Paris, 9 June 1953 - Institutional correspondence Maurice Jardot's letter to Francisco Matarazzo Sobrinho
Bonn, 16 February 1956 - Institutional correspondence Antonio Mª Aguirre's letter to Alberto Martín-Artajo Álvarez
23 February 1954 - Institutional correspondence Maurice Jardot's letter to Pablo Picasso, dated 23 February 1954
20 September 1954 - Institutional correspondence Maurice Jardot's letter to Jaime Sabartés, dated 20 September 1953