I looked and looked and finally found the mastery guides that -Hime- was referring to. They exist... sort of.
There are non-CS versions of Magic Guard 20, Magic Booster 20, and Critical Magic 15. The problem is that although the strings exist, the actual data for these items does not exist in the WZ files. There are also no references to these items anywhere in the monsterbook data or quest data. The only thing that exists is the string for each of these books.
So yeah... they went halfway on this. In short, it is completely impossible to obtain these guides unless there is a patch for the wz files. For the time being, the only way to obtain these skills is through the cash shop. So sorry to Evan players.