Tractatus:Book sources
From Tractatus
A terrific source for books for which the original copyright has expired is:
Below is a list of links to other sites that sell new and used books, and may also have further information about books you are looking for. Iain is not affiliated with any of these businesses, and this list should not be construed as an endorsement.
If you have a favorite bookseller, please let me know, and I'll add them to the list.