Chicago, 21 February 1955 - Management of reproduction rights Marilyn Vaughan's letter to Pablo Picasso
Amsterdam, 6 July 1956 - Institutional correspondence A letter from J. M. Trias de Bes to Alberto Martín-Artajo Álvarez
Madrid, 8 July 1972 - Institutional correspondence A letter from Xavier de Salas to Florentino Pérez Embid