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
Sao Paulo, 25 March 1985 and Madrid, 2 April 1985 - Institutional correspondence The loan of Guernica denied for Brazil exhibition
New York, 23 October 1969 - Institutional correspondence Elizabeth Shaw's letter to William S. Lieberman