- How does Perusall work with publishers? – Perusall. (n.d.). Retrieved May 6, 2022, from https://support.perusall.com/hc/en-us/articles/360034535073-How-does-Perusall-work-with-publishers-
- OpenStax. (n.d.). Retrieved May 6, 2022, from https://openstax.org/press/openstax-partner-schools-expected-save-students-91m-textbooks
- Hanson, M., & Checked, F. (2021, December 3). Average cost of college textbooks [2022]: Prices per year. Education Data Initiative. Retrieved May 6, 2022, from https://educationdata.org/average-cost-of-college-textbooks
- Paragraph 1: the problem of obtaining expensive course books/required readings and its solution
- https://educationdata.org/average-cost-of-college-textbooks
- https://openstax.org/press/openstax-partner-schools-expected-save-students-91m-textbooks
