*[Swift Essentials - Second Edition](https://www.packtpub.com/packt/free-ebook/swift-essentials) - Dr. Alex Blewitt, Packt (email address *requested*, not required)
*[Swift Pocket Reference](http://www.oreilly.com/programming/free/swift-pocket-reference.csp)(email address *requested*, not required)
*[Test-driven iOS Development with Swift](https://www.packtpub.com/packt/free-ebook/TDD-Swift) - Dr. Dominik Hauser, Packt. (email address *requested*, not required)
*[The Swift Programming Language](https://developer.apple.com/library/prerelease/ios/documentation/Swift/Conceptual/Swift_Programming_Language/index.html)(HTML)[(iBook)](https://itunes.apple.com/us/book/swift-programming-language/id881256329?mt=11)
