[OT] Online downloadable books

[Rodolfo Medina <rodolfo.medina@gmail.com>]

From:

 http://www.4shared.com

I downloaded a book I was looking for: Takeuti-Zaring's Introduction to
Axiomatic Set Theory.

It comes in .djvu format.  I'd be curious to know how it was formatted that
way: certainly not by scanning it page to page.

I think in future more and more books will be available on line, and many
already are; but the problem is with old editions: either scanning them page
after page, either re-write them from scratch.

Another book I was looking for: Quine's Set Theory and Its Logic, was not
anywhere in internet.  Can anyone suggest a place where it's downloadable?

Rodolfo