Bonn, 16 February 1956 - Institutional correspondence Antonio Mª Aguirre's letter to Alberto Martín-Artajo Álvarez
Mexico City, 21 April 1944 - Institutional correspondence A letter from Luis de Zulueta to Jorge Enciso
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