Madrid, 6 December 1968 - Institutional correspondence Luis Carrero Blanco's letter to Florentino Pérez Embid
Mexico City, 26 September 1968 - Institutional correspondence A letter from Rachmael ben Avram to Nelson Rockefeller
Mexico City, 26 September 1968 - Institutional correspondence Rachmael ben Avram's letter to Carol K. Uht