New York, 22 April 1960 - Institutional correspondence A letter from Jan-Albert Goris to Nelson Rockefeller, dated 22 April 1960
New York, 25 April 1960 - Institutional correspondence Jan-Albert Goris's letter to Nelson Rockefeller, dated 25 April 1960
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