Baden-Baden, 1 July 1955 - Institutional correspondence A letter from the director of the Gesellschaft der Freunde junger Kunst Baden-Baden to the Musée des Arts Décoratifs
Madrid, 19 October 1977 - Institutional correspondence Antonio Fontán Pérez's letter to Adolfo Suárez
Stockholm, 27 October and 1 de November 1956 - Institutional correspondence Memos of Swedish Foreign Ministry about the catalogue and exhibition Guernica