16 September 1960 - Internal museum documents A letter from Betsy Jones to Alfred H. Barr Jr., dated 16 September 1960
Madrid, 30 March 1988 - Internal institutional documents A letter from the director-general of Fine Arts to the Cabinet of Spain's Ministry of Culture
Madrid, 14 September 1981 - Institutional correspondence Official notice from the Management Board of Fine Arts, Archives and Museums to José Manuel Pita Andrade
New York, 6 August 1973 - Institutional correspondence A letter from Betsy Jones to Daniel-Henry Kahnweiler
New York, 18 September 1964 - Institutional correspondence A letter from Betsy Jones to Alfred H. Barr Jr., dated 18 September 1964