20 February 1980 - Institutional correspondence A letter from Ricardo de la Cierva Hoces to Adolfo Suárez
Madrid, 28 June 1980 - Institutional correspondence Ricardo de la Cierva Hoces' letter to Javier Tusell
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