Amsterdam, 6 July 1956 - Institutional correspondence A letter from J. M. Trias de Bes to Alberto Martín-Artajo Álvarez
Paris, 5 January 1953 - Institutional correspondence Letter from the Assemblé National of France to Pablo Picasso
<em>The New York Times</em>, New York, November 11, 1990, 1, 39 - Article “When Picasso Spooked the FBI”