Thanks Ankur! There are a number of reasons we split them up. First off, they are two separate exams with a large number of topics. If we had them as a single book, it would be quite large! Second, we wanted to get the first book out now so people could start studying for and taking the 1Z0-815 exam. With any luck, by the time you have passed the 1Z0-815 exam, the second book will have been released. Good luck in your studies!