Stockholm, 23 October 1956 - Institutional correspondence Ernesto de Zulueta's letter to Alberto Martín-Artajo Álvarez
Chicago, 14 September 1939 - Institutional correspondence Alice Roullier's letter to Evelyn Ahrend, dated 14 September 1939
Chicago, 12 October 1939 - Institutional correspondence Alice Roullier's letter to Evelyn Ahrend, dated 12 October 1939