rjs / ruby ajax books

what is a good book or tutorial on rjs.

i am reading the 'ajax on rails' by scott raymond and the book is
really bad. it refers to code and items that don't even exist in the
book. i thought my book was missing chapters.

Maybe others might be looking for this.
I found a concise but clearly written doucment RJS Templates for Rails
by Cody Fauser.

it a little outdated but the concepts still work.