In due course, the textbooks are rewritten and university courses are revised.

FORBES: Connect

They sell new and used textbooks and offer incentives like deep discounts, free shipping, rental programs and searchable course lists for selected major colleges and universities.

CNN: Online booksellers go back to school

When combined with the free online textbooks at sites like Textbook Revolution and TextBooksFree, plus other course books from Google Books, World Public Library, and Project Guttenberg, M.

FORBES: Free Education Is A Meme Whose Time Has Come