Affiliation
- Open Textbook Library3
- TED-Ed3
- University of Texas at Austin3
- University of Victoria3
- 國立臺灣大學3
- Abraham Baldwin Agricultural College2
- Arizona State University2
- Grand Valley State University2
- James Madison University2
- Lake Superior College2
- Lansing Community College2
- McGill University2
- Middle Georgia State University2
- North Georgia College & State University2
- University of Arkansas2
- University of Houston2
- University of Minnesota2
- University of Oklahoma2
- University of Warwick2
- Vancouver Community College2