Madrid, 2 December 1975 and Berkeley, California, 8 January 1976 - Institutional correspondence A letter from José Mario Armero to Herschel B. Chip, with reply
Madrid, 3 September - Institutional correspondence Carlos Robles Piquer's letter to Javier Tusell, dated 3 September
Madrid, 10 June 1981 - Internal institutional documents A letter from Carlos Robles Piquer to Javier Tusell
Madrid, 19 June 1981 - Institutional correspondence A letter from Carlos Robles Piquer to Javier Tusell, dated 19 June 1981