Original literary source: "Vierundzwanzig Stunden aus dem Leben einer Frau", short story by Stefan Zweig, Insel, Leipzig, 1927.
German censorship visa # 39163 delivered on 5-6-1968.
French visa # 33782.
Dominique Delouche had already written a complete script when producer Christine Gouze-Rénal asked him to take on writing associates. Which he did. Albert Valentin, who was seriously, added almost nothing to the script. As for Marie-France Rivière she enriched the dialogue. The German contributors, as far as they are concerned, did not write a line : they are only credited to justify the German side of the co-production.
The action was transposed from Monte Carlo to an Italian lake because the Monte Carlo of 1967 hadn't anything to do with what it was in the 1890s.