X + YY: Formel des Bösen
- Ár: 1970
- Land: Germany
- Genre: Crime, Thriller
- Stúdíó: Brünnstein-Film
- Lykilorð: exploitation, playboy, serial killer, hormones
- Leikstjóri: Teja Piegeler, Pavle Jovic
- Leikarar: Ljubiša Samardžić, Kai Fischer, Miloje 'Mića' Orlović, Albert Hehn, Leonina Pavlović, Stefan Zessner
