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
Brussels, 14 May 1956 - Institutional correspondence A letter from the Spanish ambassador in Belgium to Alberto Martín-Artajo Álvarez
Paris, 17 August 1937 - Newspapers The Dream and Lie of Franco. Picasso's Offering to the Spanish People