I got this email from Google Book Search about a significant upgrade to their program: reference links to your book.

I’m writing to let you know about some recent upgrades to Google Book Search. These features are designed to make Google Book Search much more comprehensive and useful for users and increase the value of the program as a book discovery tool.

On the “About this Book” page, we’ve added “References to this Book” and links to reviews on the web. If we find that your book is referenced by another book or scholarly work that we’ve scanned in Google Book Search or indexed in Google Scholar, we’ll link to the referring title. In addition, when we find a reference to a book on the web that we think is useful to users, we’ll link to the website. Finally, where possible, we’ve included links to online reviews of the book. See this example: http://books.google.com/books?vid=ISBN0395977894

In order to further enhance the user experience, we will be including results from books that we have scanned as well as books in our Bibliographic Information Index. Searching across both of these indexes will make Google Book Search much more comprehensive for users, resulting in a better user experience. This will ensure that Google Book Search continues to improve as a valuable discovery tool for your titles. Books in the Bibliographic Information Index will be presented with “no preview available.” These “no preview available” listings display only basic bibliographic information about the book, as well as the web references and reviews that we’ve found. Because we have not scanned the books, such results will only appear when the user’s query matches the title, author, or other basic information about the book.

Now, when a user searches for a book or a topic in Book Search, not only do they get the benefit of discovering books by searching across the full text, but they also will receive information about other books which, based on the title or other bibliographic information, may contain the information they’re seeking.

We welcome your feedback as we continue to improve Google Book Search and make it more comprehensive and useful.