Search for various types of OERs from a variety of publishers and contributors, including textbooks.
This is NOT a comprehensive list by any means. Just look at this as a good starting point. Please send us suggestions!
Works in the public domain are no longer protected by copyright law and may be used freely without obtaining permission from or compensating the copyright owner. In the United States, the copyright of a book expires 70 years after the author's death. Works produced by the U.S. federal government do not have copyright protection. Other rules apply in various circumstances. Visit Copyrightlaws.com to learn more about public domain.
The following websites contain eBooks that are available in the public domain.