Madrid, 22 April 1976 - Internal institutional documents A report by Joaquín de la Puente on the ownership of Guernica and the negotiation possibilities with the Museum of Modern Art, New York
Madrid, 10 September 1981 - Internal museum documents Certificate for the reception of Guernica, and its stretcher and related works
ca. 1981 - Newspapers The Guernica Imbroglio. Al international Tug-of-War over Picasso's Protest Painting
London, 7 March 1958 - Management of reproduction rights A letter from Diana K. Watson to Richard Griffith