London, 21 January 1939 - Personal correspondence Roland Penrose's letter to Pablo Picasso, dated 21 January 1939
London, 26 March 1939 - Personal correspondence Roland Penrose's Letter to Pablo Picasso, dated 26 March 1939
London, 15 April 1939 - Personal correspondence Roland Penrose's letter to Pablo Picasso, dated 15 April 1939
