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
Cambridge, Massachusetts. 29 January 1940 - Institutional correspondence A letter from Paul Sachs to Alfred H. Barr Jr.