The Library Project is an important part of Google's efforts to make it easier to find information -- in this case, the information found in print books. By partnering with libraries to digitize books from their collections, we aim to build a searchable catalog of the world's books online. The Library Project makes it possible for users to search on Google through millions of books written in many different languages, including books that are rare, out of print, or generally unavailable outside of the library system.

If a book is determined to be in the public domain, Google will make it available for full view. You'll be able read the book from start to finish. Otherwise, you'll still be able to search through the text of the book, but Google Books will only display a few snippets to show you where your search term appears, along with a few sentences of context. If the book appears to be useful to you, you can find a print copy by using the retailer or library links provided.

The Library Project makes Google Books even more useful for users, as well as providing valuable benefits to the libraries we're working with.

We're currently working with many libraries to include their collections in Google Books. You can find profiles of some of our library partners on the Google Books Library Partner page.

Libraries receive a digital copy of every book we scan from their respective collections to preserve and, where copyright law allows, to make available to their patrons.

Many of the libraries we work with have publicly displayed their contracts, which show the full scope of their work with Google. These include: the University of Michigan, the University of California, the University of Wisconsin-Madison, and the University of Texas at Austin. Though not all of the library contracts have been made public, we can say that all of them are non-exclusive, meaning that all of our library partners are free to continue their own scanning projects or work with others while they work with Google to digitize their books.

Google has developed innovative technology to scan the contents of books without harming them. In addition, we won't scan any book that we or our library partners deem too fragile, and once we've scanned a book, it is promptly returned to the library collection.

For each of the books scanned from our partner libraries, we show you basic information, like you'd see in a library catalog. If a book is determined to be in the public domain, we'll show you the full text of the book, so you can page through the book from start to finish. Otherwise, we'll show just a few snippets — sentences of your search term in context.

Please take a look at these examples to see how books are displayed in Google Books.

• Full View: Naturalis historiae by Pliny (the Elder), 1668
• Limited Preview: Castle by David Macaulay
• Snippet View: A History of Psychology by Erwin Allen Esper
• No Preview Available: A Dictionary of Zoology edited by Michael Allaby

In all cases, Google provides links that lead directly to online bookstores where you can buy the book, as well as a "Find in a library" link to help you locate a copy in a local library. (You may need to click the "Get this book in print" link to see this list.) If there is a downloadable electronic copy available, you'll see an "EBOOK" button indicating that you can either purchase it or acquire it for free.

For typical searches, querying with a keyword will provide a list of relevant books. Google Books will match the keyword against the book's bibliographic information (e.g., title, author, etc.) as well as its full text. For a more precise search, such as when you only want to find books with titles that match your keywords, visit the Advanced Search page and enter what you're searching for in the appropriate field (title, author, date, etc.). After clicking Google Search, you'll see a page with your results.

If you're interested in a book you find on Google Books, you may be able to find a copy in a local library. Click the "Find this book in a library" link to visit OCLC WorldCat ("world catalog"), where you can enter your location and find the closest library that has the book.

The link may be listed under "Get this book in print" or, for books with limited identifying information (such as no ISBN), the link may not be present.

Sometimes linking to the search results page for an author or title on Google Books isn't enough -- you want to link to a specific book or perhaps even a specific edition of a book. To help you with this, you can click the chain icon from within a book you're viewing to generate a link that you can share with others.

Google Books can also retrieve books based on International Standard Book Numbers (ISBNs), Library of Congress Control Numbers (LCCNs), and Online Computer Library Center (OCLC) record numbers. Most books published after about 1970 have ISBNs. To find a book's ISBN, search for it on Google Books and look on its "About this Book" page. For older books you may need to rely on LCCN or OCLC records.

For example, perhaps you want to link to The Prince by Machiavelli. While the book was originally published in 1532, the edition you want to link to was printed in 1988 and has an ISBN of 0521349931. You can search directly for an ISBN by visiting the following URL:

http://books.google.com/books?vid=ISBN0521349931

Similarly, you can find books by inserting the LCCN or OCLC number into the appropriate URL:

For some books, Google also provides the ability to link to specific pages of the book. (If the specific page cannot be found, the link will simply go to the "About this book" page.) Add the appropriate parameter to the book URL, as per the examples below:

If you hold the rights to a book that was scanned as part of the Library Project, you're welcome to transfer it to the Partner Program. A portion of pages will become browsable to users and you'll be able to add a link to your own website. If you're not yet participating in the Partner Program, please apply to join first. Once you have an account, you can send your transfer request to our support team.

How much more of my book will be viewable if I add it to my Partner Program account?
In order to provide a positive browsing experience on Google Books, we currently ask that at least 20% of the book be browsable. You're welcome to make more available if you wish, all the way up to setting your book to be fully browsable and even enabling free PDF downloads.

Can I get a PDF of the scanned book?
We're unable to accommodate manual requests for our scanned files. However, if you're willing to add the book to your Partner Program account and make it both 100% browsable and available for download to all users, you can acquire the PDF by visiting your book's page on Google Books.

Can I sell a digital edition of my book on Google Play using the scanned file?
Our scanned files aren't always of sufficiently high quality to offer for sale to Google Play users. We recommend that you send us a clean digital file (in PDF or ePub format) or a physical copy of your book.

How long will it take for the book to go live?
It may take up to a week for the books to be listed in your account and another two weeks for them to be live on Google Books. You can track their status from the Book Catalog page of your account. If the books are not live after that period, please contact us.

Can I replace a scanned file with a higher quality copy?
Due to technical constraints with our system, we're unable to modify or overwrite scanned files. If you anticipate being able to send us a digital file or a physical copy, we recommend that you wait until you can directly submit your book to us.

Can you scan my book?
If you would like to add a preview of your book to Google Books but you don't have a copy and it hasn't yet been scanned by Google, you can request that we scan it at one of our partner libraries. Just sign up for the Partner Program so that we can ensure the volume is associated with your account once it's scanned. As with all books digitized by Google as part of the Library Project, the source library can choose to download a copy of the scanned work.

Exclude your books from the Library Project

If you'd like to exclude your book from being scanned for the Library Project or remove the search option for a book that's already been scanned, let us know. You'll need to provide us with a small amount of information about yourself as well as a list of books you don't want to be searchable on Google Books. Unless you specify otherwise, we'll use your information only to verify that you are indeed the owner of those particular books. Please see our privacy policy for more details.

For in-copyright books scanned through the Library Project, users can preview only bibliographic information and a few short sentences of text around a search term, similar to what might be shown in a book review. Google Books never shows full pages of these books.

To prevent your books and journals from being scanned at libraries, please provide us with bibliographic information and certify that you are the owner.

• If you do not have a Google Books Partner Program account, please visit this page to submit the necessary information for the removal of your books.

• If you're a member of the Google Books Partner Program, you can do this by signing in to your account and adding the books you wish to exclude to a separate template. (You don't need to submit any content files for these books.) Once this is done, contact us with the name of the template.

An alternative to opting your book out of the Library Project is to claim the book, which adds it to your partner account. This gives you greater control over how it appears on Google Books -- for example, you can edit its metadata, enable it for preview, or even make it fully viewable. Learn more about claiming books that were scanned for the Library Project.