Interesting, but I think printed books are much better for learning, e.g. http://noBSgui.de/to/MATHandPHYSICS/ http://noBSgui.de/to/MATHandPHYSICS/ (disclaimer:

Interesting, but I think printed books are much better for learning, e.g. http://noBSgui.de/to/MATHandPHYSICS/ http://noBSgui.de/to/MATHandPHYSICS/ (disclaimer: I am the author)