vhf/free-programming-books — pull request #218 by canibanoglu (2013-10-20 22:28:19+00:00)
Title: Added Upgraded to Rails 4 github repo.

Well, this is kind of weird. The book's site is [here](http://www.upgradingtorails4.com) and it is sold through the site. But the source code has been open sourced here on GitHub and users can checkout the repo and build the book themselves.

Thought I'd send in a PR anyway :)