Madrid, 9 December 1975 - Institutional correspondence A letter from the general director of Artistic and Cultural Heritage, from Spain's Ministry of General Education
Madrid, 2 December 1975 and Berkeley, California, 8 January 1976 - Institutional correspondence A letter from José Mario Armero to Herschel B. Chip, with reply
Paris, 1 March 1975 - Personal correspondence Claude Picasso's letter to William S. Lieberman, dated 1 March 1975
Paris, 10 December 1975 - Institutional correspondence Miguel de Lojendio's letter to Spain's Ministry of Culture
Madrid, 12 December 1975 - Institutional correspondence A letter from José Mario Armero to M. Rosenthal