Madrid, 1 September 1977 - Institutional correspondence A letter from Jesús Madalena to José Mario Armero
Horseheads, New York, 23 January 1956 - Management of reproduction rights Hugh Thomas's letter to Alfred H. Barr Jr.
New York, 10 September 1981 - Internal museum documents An internal letter from Louis Estrada to Eloise Ricciardelli