Old Westbury, New York, 4 May 1977 - Institutional correspondence Emilia Doyaga's letter to Nelson Rockefeller
Madrid, 5 November 1980 - Institutional correspondence A letter from Íñigo Cavero to Blanche de Philip P. Weisberg (Blanche Mahler)
30 June 1981 - Institutional correspondence Letters from Íñigo Cavero to Pablo Picasso's heirs, dated 30 June 1981
Madrid, 13 June 1981 - Institutional correspondence Letters from Íñigo Cavero Pablo Picasso's heirs, dated 13 June 1981
Madrid, 10 September 1981 - Internal museum documents Certificate for the reception of Guernica, and its stretcher and related works
Madrid, 22 September 1936 - Institutional correspondence Francisco Sánchez Cantón's telegram to Pablo Picasso