London, 18 April 1980 - Institutional correspondence Nicholas Serota's letter to Roland Penrose, dated 18 April 1980
London, 1 May 1980 - Institutional correspondence Nicholas Serota's letter to Roland Penrose, dated 1 May 1980
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