Stockholm, 23 October 1956 - Institutional correspondence A letter from Bo Wennberg and K. G. Hulten to Pablo Picasso
Amsterdam, 6 July 1956 - Institutional correspondence A letter from J. M. Trias de Bes to Alberto Martín-Artajo Álvarez
Madrid, 17 February 1986 - Institutional correspondence Letter from Justino Azcárate to Carmen Crespo