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
ca. 1952–1956 - Internal museum documents Publicity report for the exhibition Studies for Guernica by Normal University, Illinois, addressed to the Travelling Exhibitions Department at the Museum of Modern Art, New York