In chapter 2 after Saskia was poisoned and Phillipia was talking about what she needs for a cure there was a great reference to the Lord of the Rings. I forget the exact word but it was soemthing like this:
Phillipia said she needed a magical item like one of the 20 rings of power.
Iroveth: "One ring to bring them all together and in the darkness bind them."
Geralt: "I'm not going barefoot to some volcano searching for a ring of power."
Phillipia: "Ok we'll use some other magical item then."
Yeah, it's something more like,
Philippa: "...then there're the one of 10 magic rings of power scattered across the land..."
Iorveth: "One to gather, and in the darkness bind them all?"
Geralt: "Yeah, and next thing you know I'll be running barefoot to the top of some volcano."
Philippa: "Okay, okay, forget the rings...."