Roxbury, 22 November 1955 - Institutional correspondence Alexander Calder's letter to Willem Sandberg, dated 22 November 1955
Roxbury, 12 January 1956 - Institutional correspondence Alexander Calder's letter to Willem Sandberg, dated 12 January 1956
Madrid, 22 September 1936 - Institutional correspondence Francisco Sánchez Cantón's telegram to Pablo Picasso
1939 - Institutional correspondence Acceptance letters from Alfred H. Barr Jr., Aleksina Matisse, Georgia O'Keefe and Sidney Janis to Caspar Whitney