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
Princeton, 8 December 1956 - Institutional correspondence A letter from Kazuko Higuchi to Alfred H. Barr Jr.