I bought an access code, but it does not work!

Please make sure you have not entered the Redemption Code on the publisher's website, only via the Bookshelf app. Simply add the purchased Redemption Code on the bookshelf in the app, redeem it and once the book appears on the bookshelf, click the "Reveal Access Code" directly. Only the revealed code can be entered on the publisher's website. Please note, the exact Course ID is required for certain access codes without knowing which code will not work.