You can get online peer-reviewed books for free. They can be also be purchased in softcover, audio, and self-print versions. They are open-source so you can modify them to fit your course. Faculty receives great books and control over their content. THEY get to decide when to move to a new version, not the publisher and the student wins.
Check to see if your university is listed (there are 100’s of them here!) and then sort alphabetically by school name and use the alpha links to jump to your school.