Bonn, 16 February 1956 - Institutional correspondence Antonio Mª Aguirre's letter to Alberto Martín-Artajo Álvarez
New York, 10 July 1939 - Institutional correspondence Blanche Mahler's letter to Grace L. McCann Morley
2 May 1939 - Internal institutional documents A draft text for the invitation to the exhibition Picasso's Guernica at the Valentine Gallery, New York
ca. 1981 - Newspapers The Guernica Imbroglio. Al international Tug-of-War over Picasso's Protest Painting