Hello,

On Fri, 17 Jun 2005 15:13:25 +0900, Charles E. Thornton  
<ruby-core / hawthorne-press.com> wrote:

> What I have is not a book, but  a collection of html files that explain  
> various aspects
> of Ruby. (It is however attributed to 'Minero Aoki')
>
> But these do not appear anywhere near a 'book'.

Aoki-san did make a book and he has kindly released it on the web.
What you are linking to, appears to be an earlier rough draft of his
work.  Here are links to the complete book:

HTML version of the Ruby Hacking Guide
http://i.loveruby.net/ja/rhg/index.html

Below is a page with errata, examples, the above HTML, a downloaded
package of the HTML, etc..

http://i.loveruby.net/ja/rhg/

Cheers,
Zev