Unlike other forms of Google search, Google does not display advertising to book searchers, nor does it receive payment if a searcher uses Google’s link to buy a copy. Google’s book scanning project started in 2004. Working with major libraries like Stanford, Columbia, the University of California, and the New York Public Library, Google has scanned and made machine-readable more than 20 million books. Many of them are nonfiction and out of print.
How is the world connected? The Global Language network shows connections among language groups that are expressed in Book Translations, Tweets and Wikipedia edits.
Source : Global Language Network