New York, 3 December 1957 - Internal museum documents A letter from Dorothy C. Miller to Monroe Wheeler
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
New York, 3 May 1968 - Institutional correspondence Dorothy C. Miller's letter to Daniel-Henry Kahnweiler
New York, 21 February 1966 - Management of reproduction rights Dorothy C. Miller's letter to Pearl Moeller