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, 19 October 1977 - Institutional correspondence Antonio Fontán Pérez's letter to Adolfo Suárez
Madrid, 10 September 1981 - Internal museum documents Certificate for the reception of Guernica, and its stretcher and related works