New York, 16 January 1957 - Institutional correspondence Alfred H. Barr Jr.'s letter to Roland Penrose, dated 16 January 1957
London, 18 April 1980 - Institutional correspondence Nicholas Serota's letter to Roland Penrose, dated 18 April 1980
London, 1 May 1980 - Institutional correspondence Nicholas Serota's letter to Roland Penrose, dated 1 May 1980
22 May 1957 - Press release and communication A press release on the publication of Portrait of Picasso, by Roland Penrose