Amsterdam, 19 June 1956 - Internal museum documents History, chronology of Picasso and a report on Rodin's exhibition project
Amsterdam, 1956 - Internal museum documents A checklist for the Guernica studies, insurance costs and notes.
Amsterdam, 1956 - Internal museum documents A packing list of studies for Guernica with titles and measurements
Roxbury, 12 January 1956 - Institutional correspondence Alexander Calder's letter to Willem Sandberg, dated 12 January 1956