Roxbury, 22 November 1955 - Institutional correspondence Alexander Calder's letter to Willem Sandberg, dated 22 November 1955
New York, 17 July 1968 - Internal museum documents Jean Volkmer's letter to Bates Lowry, dated 17 July 1968
Roxbury, 12 January 1956 - Institutional correspondence Alexander Calder's letter to Willem Sandberg, dated 12 January 1956
New York, 17 July 1968 - Internal museum documents Jean Volkmer's letter to Bates Lowry, dated 17 July 1968