New York, 12 March 1956 - Institutional correspondence Bernard Karpel's letter to Willem Sandberg, dated 12 March 1956
New York, 27 November 1956 - Institutional correspondence Bernard Karpel's letter to Willem Sandberg, dated 27 November 1956
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
ca. 1952–1956 - Internal museum documents Publicity report for the exhibition Studies for Guernica by the Berea College Art Department, Kentucky, addressed to the Travelling Exhibitions Department at the Museum of Modern Art, New York