documentation relevant to 4.x?

Is there an online version of the latest documentation that pertains to Unity 4? I know it's being wound down, but some improvements are still supposedly coming to that version. So, an archived version of the documentation works, but is less than ideal.

I've been in the habit of just using the primary documentation, which describes Unity 5, but more and more, I'm bumping into features that just aren't available in my version. Unfortunately, I have some dependencies on Unity 4 that I can't easily shrug off.