Roxbury, 22 November 1955 - Institutional correspondence Alexander Calder's letter to Willem Sandberg, dated 22 November 1955
Paris, 28 October 1953 - Institutional correspondence Maria Oliva Fraga's letter to Arturo Profili, dated 28 October 1953
Paris, 5 November 1953 - Institutional correspondence Maria Oliva Fraga's letter to Arturo Profili, dated 5 November 1953
Roxbury, 12 January 1956 - Institutional correspondence Alexander Calder's letter to Willem Sandberg, dated 12 January 1956