Artemis Fowl: The Arctic Incident Easter Eggs

At the bottom of the pages of the main story, there is a code in Centaurian. When translated into English it reads:
Congratulations, human. If you have cracked this code, you are more intelligent than most of your species. This is a message from the... more

If you turn to Chapter 3: Going Underground, pages 48 and 49 in the original style, Butler will mention a false name: "How about Stefan Bashkir and his uncle Constantin?" It is apparently a well-used cover for them.

But this is also a reference to... more