I couldn't find it under Open Access. It's unfortunate. At a $104 I can't afford to buy. But I would love to read -- I would gladly pay $20 or so for an ebook.
Look the page in a desktop browser. Directly below the book's cover, there's a “Resources”. To the right of that “Resources”, there are “Overview”, “Author(s)”, “Open Access”; and that “Open Access” is the one you want.