I checked about a minute before posting just to be sure, and I've just checked right now.
It is available in the sense that you can buy it from a third party (i.e., an independent seller), but not from Amazon itself. This appears to suggest the book is out of print. Is that not the case?
In either event, the link on the above page leads to this page:
http://www.amazon.com/gp/offer-listi...&condition=new
... which is a list of third party vendors.