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
Amsterdam, 19 July 1956 - Internal museum documents Willem Sandberg's letter to Amsterdam City Council, dated 19 July 1956
