New York, 26 June 1978 - Institutional correspondence A letter from Judith Cousins to William Burback
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
<em>The New York Times</em>, New York, September 28, 1969, section D, 35 - Article “Keeping Art On The Streets”