You gotta get lucky and catch an auction or someone putting it up on eBay for a reasonable amount. That's how I did it :)
Another way is to go to your local library and request that they borrow a copy for you. Usually libraries have no problem loaning out the book from another library that has...
It was never meant to be a PDF, the PDF was created and uploaded without permission. So basically the PDF existing is piracy, which is probably why it's basically impossible to find now.
But if you can find a physical copy of the book, it's got a lot of good info. I frequently reference my...