About > Our Guarantee
All our books come with an unconditional guarantee.
If you are not completely satisfied with a book for any reason, please let us know -- we will gladly issue a full refund or an exchange, regardless of where you purchased the book.
Our books are sold to bookstores on a "firm sale" basis, so your bookstore may or may not accept returns themselves (depending on their own policy).
However, do not worry---you can always return a book directly to us and we will refund the full cost of the book and return shipping. To begin the returns process, please send us an email with details of your purchase and why you are disappointed (contact information).
If a bookstore incorrectly sends you an old version of a book after we have released a new version, just contact us and we will replace it with the latest version free of charge.
If there is a production issue with any book (e.g. damaged cover, missing pages) your bookstore can obtain a replacement from their wholesale supplier for you, free of charge. If there are problems getting them to do this, let us know and we will ship a replacement copy to you immediately.
If you've purchased one of our books and find an error in it you can report it to us and we will submit a patch to the maintainer. If the error was not previously listed on this website you'll be entitled to a free copy of the next edition when it is published.
June 2003 (updated September 2004, March 2007)
Network Theory Ltd