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
Zurich, 12 December 1955 - Institutional correspondence A letter from Klaus Herdeg to Willem Sandberg
Cambridge, Massachusetts. 29 January 1940 - Institutional correspondence A letter from Paul Sachs to Alfred H. Barr Jr.