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, 15 March 1986 - Institutional correspondence Letter from Alfonso E. Pérez Sánchez to Dionisio Hernández Gil
New York and Madrid, June 1988 - Institutional correspondence Correspondence between William Rubin and Alfonso E. Pérez Sánchez