Many commercial publishers are making texts and other materials available as OERs during the COVID-19 pandemic.
OA textbooks are freely available online to all users.
All ebooks in the GSU library collection can be located in the library catalog, GILFind. Search by topic as normal, then select "Full Access Online" under Availability, and "Books" under format to limit your results to ebooks.
Some library ebooks have a limited number of simultaneous users. Ask your subject librarian for help if you have questions.