It's a great book but PLEASE DON'T BUY IT FROM EDUCREATION PUBLISHING
THEY DONT HAVE THE RIGHTS TO SELL IT AND THE AUTHOR HAS FILED A CASE AGAINST THEM
It was published on a self publishing order on demand contract where authors have to pay yearly for publishing but the goons at educreation refuse to take it down from any platform despite many requests and warnings from the author and don't pay the due royalty either.
THE MATTER IS SUBJUDICE IN COURT