How to get the release version of Apple's "The Swift Programming Language" iBook
This is the release version: 
https://itunes.apple.com/us/book/swift-programming-language/id881256329?isInPurchasedView=true&amp;mt=11

This is the prerelease version: 
https://itunes.apple.com/us/book/swift-programming-language/id1002622538?isInPurchasedView=true&amp;mt=11