I see, you added the movie for the other girls named in the cast list, too.
Here are the one's you couldn't decipher:
Romanina = Vanessa Smoke
Renata = Renata Black
Valery Hilton = Sabrina White
Jennifer = Fiorina Rose / Jennifer Love
Kleo La Roux = Kleopatra Caszo
(anal for everyone)
which leaves the name "Sonia" from the cast list for Gabriella Sweet.
Funny though, that the girls are appropriately named in the titles but not on the DVD cover.
If you need more proof, I'll take more screenshots.