Roxbury, 22 November 1955 - Institutional correspondence Alexander Calder's letter to Willem Sandberg, dated 22 November 1955
Roxbury, 12 January 1956 - Institutional correspondence Alexander Calder's letter to Willem Sandberg, dated 12 January 1956
22 November 1980 - Institutional correspondence Rafael Fernández Quintanilla's letter to Javier Tusell, dated 22 November 1980
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