Amsterdam, 16 January 1957 - Institutional correspondence A telegram from Willem Sandberg to Alfred H. Barr Jr.
New York, 23 January 1957 - Transport documents A letter from the vice-president of W. R. Keating & Company to Willem Sandberg
Amsterdam, 28 January 1957 - Institutional correspondence Willem Sandberg's letter to Robert Giron, dated 28 January 1957
Amsterdam, 28 January 1957 - Institutional correspondence Willem Sandberg's letter to Bo Wennberg, dated 28 January 1957
Amsterdam, 18 April 1956 - Press release and communication Picasso's Guernica and studies will be at the Stedelijk Museum from mid-July to the end of September
Rotterdam, 1956 - Transport documents A contract from the transport company Holland-Amerika Lijn for the delivery of Guernica and studies to New York