royal wrote: You're going to notice that with any certification books. No one certification book will contain all the information you need for everything. Many people actually use a couple books to make sure they get as much information as possible to learn as possible to be as prepared as possible for the exam. It's good that you went and studied off of another book, and you are finding additional information. We all go through this, hence the reason why many of us use a 2nd book.