New York, 12 March 1956 - Institutional correspondence Bernard Karpel's letter to Willem Sandberg, dated 12 March 1956
New York, 27 November 1956 - Institutional correspondence Bernard Karpel's letter to Willem Sandberg, dated 27 November 1956
Paris, 1937 - Photograph Inside the Spanish Pavilion at the Paris International Exhibition of Art and Technology in Modern Life. Pablo Picasso's Guernica and the Mercury Fountain, by Alexander Calder