HathiTrust This link opens in a new windowHathiTrust is a large-scale collaborative repository of digital content from research libraries. It includes content digitized as part of the Google Books project and Internet Archive digitization initiatives, as well as content digitized locally by member libraries. Materials are available to the extent permitted by copyright law. As of March 2015, the HathiTrust digital library contained over 13 million digitized volumes, of which almost 5 million volumes were in the public domain (source: http://www.hathitrust.org/statistics_visualizations).