The I Ching is non-linear; you must constantly flip back and forth between different hexagrams, trigram charts, and line commentaries. A physical book or a properly indexed, legally purchased e-book with interactive hyperlinks offers a vastly superior user experience compared to a poorly scanned, pirated PDF document.
One advantage of an (or ebook) is the search functionality. If you perform an I Ching reading using coins or yarrow stalks, you will land on a specific hexagram number (e.g., Hexagram 24, Return ). In a digital format, you can instantly search for "Hexagram 24" or use the table of contents hyperlink to jump to the reading. alfred huang i ching pdf