New York, 12 March 1956 - Institutional correspondence Bernard Karpel's letter to Willem Sandberg, dated 12 March 1956
New York, 27 November 1956 - Institutional correspondence Bernard Karpel's letter to Willem Sandberg, dated 27 November 1956
Paris, 18 October 1948 - Institutional correspondence A letter from Mariano Miguel to José Ballester-Gozalvo
Mougins, 10 December 1970 - Personal correspondence A telegram Mariano Miguel, Picasso’s secretary, sent to Raimon Noguera to request the cancellation of the opening ceremony for the expansion of Museo Picasso