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
1939 - Institutional correspondence Acceptance letters from Alfred H. Barr Jr., Aleksina Matisse, Georgia O'Keefe and Sidney Janis to Caspar Whitney