Paris, 14 October 1955 - Institutional correspondence A letter from the Société de la Propriété Artistique et des Dessins et Modèles (S.P.A.D.E.M.) to the Musée des Arts Décoratifs
Amsterdam and Brussels, 1956 - Exhibition catalogue Guernica: avec 60 études et variantesGuernica: met 60 studies et varianten
1956 - Conferences and articles Text by Emil Langui for the exhibition catalogue Guernica, avec 60 études
Brussels, 19 July 1957 - Institutional correspondence A letter from Émile Langui to Pablo Picasso, 19 July 1957
Brussels, 19 July 1957 - Institutional correspondence Émile Langui's letter to Pablo Picasso, dated 19 July 1957
Brussels, 6 September 1957 - Institutional correspondence Émile Langui's letter to Pablo Picasso, dated 6 September 1957