[Armin shakes his head a little.]

I've tried reading up on them, but most books available are, well...

[Allow him to duck back into the tent and dig through his backpack, digging out a book that is bright and colourful and very much meant for young children children.]

It's this sort of stuff. It is hard to say if anything in this is dependable. And even if it is, most of the information in it is very basic.