Philadelphia, 15 April 1945 - Institutional correspondence Madelin Blitzstein's letter to Pablo Picasso
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