New York, 16 September 1957 - Institutional correspondence A letter from Monroe Wheeler to Katharine Kuh
Madrid, 31 July, and Cambridge, Massachusetts, 31 August 1981 - Institutional correspondence Álvaro Martínez Novillo's letter to Josep Lluís Sert, with reply
Madrid, 29 May and 10 June 1981 - Institutional correspondence A letter from Felipe Cons Gorostola to Álvaro Martínez Novillo, and reply
New York, 3 September 1981 - Internal institutional documents Inventory and conservation report on the works collected by New York's Museum of Modern Art to be sent to Spain
Madrid, 8 February 1982 - Institutional correspondence A letter from Álvaro Martínez Novillo to Pedro J. Ramírez
New York, 6 September 1966 - Institutional correspondence Monroe Wheeler's letter to Alfred H. Barr Jr.
New York, 8 September 1981 - Internal institutional documents A confidential and private document signed by Álvaro Martínez-Novillo and José María Cabrera in New York
New York, 6 December 1957 - Institutional correspondence Monroe Wheeler's letter to Dorothy Miller and Alfred H. Barr Jr.