Madrid, 6 December 1968 - Institutional correspondence Luis Carrero Blanco's letter to Florentino Pérez Embid
New York, 17 July 1968 - Internal museum documents Jean Volkmer's letter to Bates Lowry, dated 17 July 1968
New York, 17 July 1968 - Internal museum documents Jean Volkmer's letter to Bates Lowry, dated 17 July 1968
ca. 1952–1956 - Internal museum documents Publicity report for the exhibition Studies for Guernica by the University of Minnesota Gallery, addressed to the Travelling Exhibitions Department at the Museum of Modern Art, New York