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
Paris, 6 September 1939 - Institutional correspondence Christian Zervos's letter to Alfred H. Barr Jr., dated 6 September 1939
Paris, 27 December 1939 - Institutional correspondence Christian Zervos's letter to Alfred H. Barr Jr., dated 27 December 1939
Paris, 26 October 1939 - Institutional correspondence Christian Zervos's letter to Alfred H. Barr Jr., dated 26 October 1939