Mexico City, 26 September 1968 - Institutional correspondence Óscar Urrutia's telegram to Carol K. Uht
Madrid, 3 September - Institutional correspondence Carlos Robles Piquer's letter to Javier Tusell, dated 3 September
Madrid, 10 June 1981 - Internal institutional documents A letter from Carlos Robles Piquer to Javier Tusell
Madrid, 19 June 1981 - Institutional correspondence A letter from Carlos Robles Piquer to Javier Tusell, dated 19 June 1981
ca. 1952–1957 - Internal museum documents Publicity report for the exhibition Studies for Guernica by the Kansas State Teachers College, Pittsburg, addressed to the Travelling Exhibitions Department at the Museum of Modern Art, New York