Stockholm, 23 October 1956 - Institutional correspondence Ernesto de Zulueta's letter to Alberto Martín-Artajo Álvarez
New York, 20 March 1980 - Internal institutional documents An agreement over the conditions and delivery date of Guernica
Bonn, 16 February 1956 - Institutional correspondence Antonio Mª Aguirre's letter to Alberto Martín-Artajo Álvarez
Brussels, 14 May 1956 - Institutional correspondence A letter from the Spanish ambassador in Belgium to Alberto Martín-Artajo Álvarez
Amsterdam, 6 July 1956 - Institutional correspondence A letter from J. M. Trias de Bes to Alberto Martín-Artajo Álvarez
Oslo, 27 November 1956 - Institutional correspondence A letter from Miguel de Aldasoro to Alberto Martín-Artajo Álvarez
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
Madrid, 23 and 25 September 1980 - Institutional correspondence Alejandro de Muns' letter to Javier Tusell, with reply
3 October 1980 - Internal institutional documents A confidential letter from Spain's Ministry of Culture regarding negotiations for Guernica
Madrid, 5 November 1980 - Institutional correspondence A letter from Íñigo Cavero to Blanche de Philip P. Weisberg (Blanche Mahler)
1980 - Internal institutional documents Report by the Management Board of Artistic Heritage, Archives and Museums on the moral rights and legislation with regard to Guernica
Madrid, 11 December 1980 - Internal institutional documents Javier Tusell's report on negotiations for the transfer of Guernica