Free Digital Collections with Primary Sources
The Biodiversity Heritage Library improves research methodology by collaboratively making biodiversity literature openly available to the world as part of a global biodiversity community.
Provides links to primary source collections in: Biology & Natural History, Chemistry, Computer Science, Engineering & Technology, Environment/Forestry/ Agriculture, Medicine, Physics, and General STEM.
A non-profit library of millions of free books, movies, software, music, websites, and more
Many libraries and museums house primary sources. This website will search digital repositories of open-access content!
Primary source collections exploring topics in history, literature, and culture developed by educators — complete with teaching guides for class use.
HathiTrust is a partnership of academic & research institutions, offering a collection of millions of titles digitized from libraries around the world.
Nearly 48,000 digitized books as of 2015. All in the public domain (in general, published before 1923). Available in epub, kindle, PDF or to be read online. Over 50 languages. Great source for classics and historical works.