Good cheap/free book?

Hi! I know this might be a cliche’ , but where can I find a great book on Unreal Engine 4 that is also cheap or has some kind of student discount? I am specifically looking for one that teaches C++ UE4, maybe some other stuff too, but uses C++ as it’s main trade tool. I am not looking for Blueprint-based tutorials. Also, I’m looking for one that assumes the reader knows C++ in-depth, or at least to some medium-level extent. Thanks!

here is 2 best free books ever :

and an ebook on how did he made the best scene you can find the link at the bottom of the page “Download FREE 51-Page Case-Study PDF: “How I Created The Corridor in 10 Hours with UE4”:”