Copenhagen, 31 October 1956 - Institutional correspondence Lars Rostrup Boyesen's letter to Pablo Picasso
Copenhagen, 31 October 1956 - Institutional correspondence Lars Rostrup Boyesen's letter to Daniel-Henry Kahnweiler
Copenhagen, 31 October 1956 - Institutional correspondence Lars Rostrup Boyesen's letter to the Museum of Modern Art, New York
Madrid, 19 October 1977 - Institutional correspondence Antonio Fontán Pérez's letter to Adolfo Suárez
Gernika, 6 April and Madrid, 9 April 1987 - Institutional correspondence Correspondence on the Gernika 37-87 commemoration acts