Minneapolis, 18 January 1962 - Institutional correspondence Wayne W. Andersen's letter to Nelson Rockefeller
Yonkers, 20 March 1969 - Institutional correspondence Donald M. Jr. Halley's letter to Nelson Rockefeller
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
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