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
Exhibition, MoMA, New York, June 2, 1967 – February 13, 1968 - Photograph View of the exhibition Guernica: Studies and Postscripts