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
<em>Parabólica Magazine</em>, Seville, special number, November 2004 - Magazine “A propósito de la BIACS: políticas culturales” (“About BIACS: Cultural Policies”)