Madrid, 29 May and 10 June 1981 - Institutional correspondence A letter from Felipe Cons Gorostola to Álvaro Martínez Novillo, and reply
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