↑ Pace, Andrew K. (January 2006). "Is This the Renaissance or the Dark Ages?". American Libraries. American Library Association. Diarkibkan daripada asal pada 2007-04-03. Dicapai 2007-04-11. Google made instant e-book believers out of skeptics even though 10 years of e-book evangelism among librarians had barely made progress.
1 2 Malte Herwig, "Google's Total Library", Spiegel Online International, Mar. 28, 2007.
↑ "Books of the world". August 5, 2010. Dicapai 2010-08-15. After we exclude serials, we can finally count all the books in the world. There are 129,864,880 of them. At least until Sunday
