Baden-Baden, 1 July 1955 - Institutional correspondence A letter from the director of the Gesellschaft der Freunde junger Kunst Baden-Baden to the Musée des Arts Décoratifs
Madrid, 21 February 1969 - Institutional correspondence Florentino Pérez-Embid's letter to Joaquín de la Fuente
Hollywood, 21 October 1939 - Institutional correspondence H. Heyman's and G. E. Scheyer's letter to Sidney Janis