Cambridge International AS & A Level Computer Science Revision Guide

If you are looking for an A* this book is not going to give you one. I find Z-notes way more useful than this book. It is almost as if the author avoids answering the questions in the spec and simply mentions them here.

Good textbook to have, like all text books for A/As level CIE computer science, you have to use multiple, none of them cover quite enough in the right amount of detail to answer all exam questions.