Of course, individuals write open textbooks for use in the higher education context as well. Several sites exist that catalog these individual contributions (and sometimes the institutional contributions as well). These sites include OER Commons (Links to an external site.) (use the advanced search to limit your search to textbooks), Open Textbook Store (Links to an external site.), and Open College Textbooks (Links to an external site.). You can also use Google advanced search to find open textbooks - for example, search for "political science textbook" and restrict the search to openly licensed results.
https://learn.canvas.net/courses/4/pages/the-open-textbook-catalog?module_item_id=52607
