[C] seeking good books

I suppose everybody here read reference books like Kernighan & Ritchie one, but where's the real deal?

I mean I'd like to learn more about special efficient techniques, tips&tricks, what compiler effectively does, and stuff like that.

Could you please suggest me some books or internet resources you found very helpful about C programming?

Numerical recipes in C is a book that is used a lot and with many useful programming techniques. Most expertise these days is garnered straight from the internet forums.