| Source |
|---|
| 2012 Book Archive |
| Affordable Learning Georgia |
| Bay College OER |
| BCcampus Open Textbooks |
| Bookboon |
| California Open Online Library for Education (COOL4ED) |
| Center for Open Educational Resources and Language Learning |
| CK-12 |
| Community College Consortium |
| Directory of Open Access Books |
| FreeTechBooks |
| Galileo |
| InTech |
| Lake Tahoe Community College CCC OER List |
| LibreTexts |
| Literature in Context: An Open Anthology of Literature in English, 1400-1925 |
| Mason OER Metafinder |
| Michigan Open Textbook Project (3-12) |
| National Academies Press |
| NCBI (science and health) |
| OASIS |
| OER Commons |
| Open Oregon |
| OpenStax |
| OpenTextBookStore |
| Open Textbook Library |
| San Bernardino Valley College |
| Saylor Academy |
| Siyavula (4-12) |
| University of Hawaii Pressbooks |
| University of South Florida Scholar Commons |
| Wikibooks |