Madrid, 6 December 1968 - Institutional correspondence Luis Carrero Blanco's letter to Florentino Pérez Embid
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