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
Northampton, Massachusetts, 16 May 1939 - Institutional correspondence Jere Abbott's letter to Sidney Janis
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