Apple issued for developers to provide free ebook

Apple (Apple) has just released six this free ebooks, looks are for developers gift. According to the news of the Cult to Mac, these books include:

Cocoa Fundamental 's Guide;
The Objective-C Programming Language;
IOS Application Programming Guide;
Object Oriented Programming With Objective-C;
IOS Technology Overview;
IOS Human Interface Guidelines;

These the ebook is not new, but the first day they landed in iBooks platform,
formerly of the developers can only through the developer. Apple. Com online reading or download the PDF study.