Paris, 30 October 1971 - Institutional correspondence A letter from Luis López Ballesteros to Alfredo Sánchez Bella
ca. 1952–1956 - Internal museum documents Publicity report for the exhibition Studies for Guernica by Normal University, Illinois, addressed to the Travelling Exhibitions Department at the Museum of Modern Art, New York
New York, 27 August 1980 - Institutional correspondence A letter from Eleanor L. Saxe to William Rubin, Sharon Zane and others