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, 1981 - Photograph Placing the reproduction of Guernica for the test installation in the Casón del Buen Retiro
ca. 1952–1956 - Internal museum documents Publicity report for the exhibition Studies for Guernica by the University of Minnesota Gallery, addressed to the Travelling Exhibitions Department at the Museum of Modern Art, New York