Madrid, 2 December 1975 and Berkeley, California, 8 January 1976 - Institutional correspondence A letter from José Mario Armero to Herschel B. Chip, with reply
ca. 1952–1956 - Internal museum documents Publicity report for the exhibition Studies for Guernica by Allegheny College, Meadville, Pennsylvania, addressed to the Travelling Exhibitions Department at the Museum of Modern Art, New York