Yonkers, 20 March 1969 - Institutional correspondence Donald M. Jr. Halley's letter to Nelson Rockefeller
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