Books (was:Re: What features do P-I-E languages have in common?)

At 19:05 17/07/03, Jesse S. Bangs <jaspax@...> wrote:

>I have read that book, though I didn't recall the llama discussion. IMHO,
>_Guns, Germs and Steel_ does for conculturing what _Describing
>Morphosyntax_ does for conlanging--it's an indispensible source of
>explanations and ideas.
Clearly I'll have to get both.  At least once I have some money again, if
ever I do. :/

Could you provide references?

And while I'm at it, I've been meaning to ask: what other books, if any,
are very useful to conlanging?  (or, indeed, conculturing!)

Ian