The link provided is the TOC of the book in website form; the “Article Sections”[1] and “Commentary Sections”[2] links lead to more conventional sub-TOCs (or are supposed to, they seem to be incomplete). It doesn’t look like there is a download.
Yeah, I was also confused by this. What kind of e-book can't be downloaded or viewed as some type of file? If we relax the definition of book to include this, how is a book different from a set of webpages?
The content looks good, but it's hard to find things when it's spread across so many individual pages.