New York, 20 March 1980 - Internal institutional documents An agreement over the conditions and delivery date of Guernica
May, 1992 - Newspapers Solé Tura promises the Prado financial compensation in exchange for the transfer of Guernica
20 February 1980 - Institutional correspondence A letter from Ricardo de la Cierva Hoces to Adolfo Suárez
New York, 24 March 1980 - Institutional correspondence A letter from Richard Oldenburg and William Rubin to Javier Tusell
Madrid, 28 June 1980 - Institutional correspondence Ricardo de la Cierva Hoces' letter to Javier Tusell
Madrid, 11 September 1980 - Institutional correspondence Javier Tusell's letter to José Pedro Pérez-Llorca