This appendix provides a list of references that you should find helpful. They are listed in three categories for ARC, Blocks, and Grand Central Dispatch.
References for ARC
Transitioning to ARC Release Notes
ARC Programming Guide by Apple
When you want to know something about ARC, you should read this document first. If you’re reading this book before it, it is ok :-), but you should read it later.
LLVM Document—Automatic Reference Counting
This document is something like the specification of ARC. When you want to make sure of its specification, please check this ...