Mainz, 2 May 1956 - Institutional correspondence J. Mougin's letter to François Mathey, dated 2 May 1956
Paris, 14 March 1956 - Personal correspondence Daniel-Henry Kahnweiler's letter to Pablo Picasso, dated 14 March 1956
Oslo, 27 November 1956 - Institutional correspondence A letter from Miguel de Aldasoro to Alberto Martín-Artajo Álvarez