To calculate the overall star rating and percentage breakdown by star, we don’t use a simple average. Instead, our system considers things like how recent a review is and if the reviewer bought the item on Amazon. It also analyses reviews to verify trustworthiness.
I just received the book. The poduct is a duplicate copy of the original as the quality of the book andb the subsequent print issues in the book have made it evident. I would recommend to buy the same from another vendor.