São Paulo, 28 December 1953 - Institutional correspondence Francisco Matarazzo Sobrinho's letter to Daniel-Henry Kahnweiler
São Paulo, 14 February 1954 - Institutional correspondence Francisco Matarazzo Sobrinho's letter to Pablo Picasso, dated 14 February 1954
São Paulo, 4 February 1954 - Institutional correspondence Francisco Matarazzo Sobrinho's letter to Pablo Picasso, dated 4 February 1954
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
São Paulo, 26 December 1952 - Institutional correspondence Francisco Matarazzo Sobrinho's letter to Pablo Picasso, dated 26 December 1952