As Sylvia there is called the name of Sandrine Dumas but it is Sandra Dumas a dutch model in those years. She only made her appearance in Twice a Woman (Twee Vrouwen). There is now (2008) a new RESTORED release of that PICTURE as part of "Beelden voor de Toekomst" from the Dutch Filmmuseum e.a. Completely remastered and part of two copies re-aranged and fixed in association with the director George Sluizer. He managed to get two Hollywood stars in his picture. Bibi Anderson and Anthony Perkins. An unicum in dutch filmhistory in that time. But it still is a brilliant piece of work. Both the writer (Harry Mulisch) as the director.