Milan, 4 August 1953 - Institutional correspondence A letter from Fernanda Wittgens to Willem Sandberg, dated 4 August 1953
Milan, 12 August 1953 - Institutional correspondence Fernanda Wittgens' letter to Willem Sandberg, dated 12 August 1953
Milan, 7 October 1953 - Institutional correspondence A letter from Fernanda Wittgens to Willem Sandberg, dated 7 October 1953
<em>The Museum of Modern Art at Mid Century, At Home and Abroad; Studies in Modern Art 4</em>, New York: MoMA, 1994, 38–55 - Article “Revisiting the Revisionists: the Modern, its Critics, and the Cold War”