20 February 1980 - Institutional correspondence A letter from Ricardo de la Cierva Hoces to Adolfo Suárez
Madrid, 28 June 1980 - Institutional correspondence Ricardo de la Cierva Hoces' letter to Javier Tusell
May - July 1992 - Institutional correspondence Loaned works at the Museo Nacional Centro de Arte Reina Sofía in conjunction with the rearrangement of holdings between the Reina Sofía and Museo Nacional del Prado
Madrid, 8 February 1995 - Internal institutional documents A loan approval form for the exhibition Picasso: The Love and the Anguish. The road to Guernica