Roxbury, 22 November 1955 - Institutional correspondence Alexander Calder's letter to Willem Sandberg, dated 22 November 1955
Cambridge, Massachusetts, 8 December 1955 - Institutional correspondence Josep Lluís Sert's letter to Willem Sandberg
Amsterdam, 8 November 1955 - Institutional correspondence Willem Sandberg's letter to Alexander Calder, dated 8 November 1955
Amsterdam, 30 November 1955 - Institutional correspondence Willem Sandberg's letter to Alexander Calder, dated 30 November 1955
Amsterdam, 2 December 1955 - Personal correspondence Willem Sandberg's letter to Maurice Lefebvre-Foinet, dated 2 December 1955
Paris, 5 December 1955 - Institutional correspondence Maurice Lefebvre-Foinet's letter to Willem Sandberg
Amsterdam, 9 December 1955 - Personal correspondence Willem Sandberg's letter to Maurice Lefebvre-Foinet, dated 9 December 1955
Roxbury, 12 January 1956 - Institutional correspondence Alexander Calder's letter to Willem Sandberg, dated 12 January 1956
Amsterdam, 23 January 1956 - Institutional correspondence Willem Sandberg's letter to Alexander Calder, dated 23 January 1956
Valencia, 22 October 1937 - Institutional correspondence Telegram from the Embassy of Spain in France to the Minister of State
París, 21 October 1937 - Photograph Albert Lebrun, President of the French Republic, visits the Spanish Pavilion