Need to master Core Data? I finished reading one book right now, it’s really great.
I spent lot of time reading Core Data: Data Storage and Management for iOS, OS X, and iCloud (Pragmatic Programmers) and learning from it. It’s a great book - if you know something about Core Data and you want to read more about it, about performance and how it works and what’s behaviour of the Core Data from inside, this book is for you. Also you may find these links useful for further reading: