Greetings!
I'm not new to these kind of stuff,I have read plenty of books,watched a lot of videos about approaching or something similar about that,but something is simply missing..
First of all,I think that I have certain amount of knowledge,but I'd like to learn even more.So, if anyone can recommend me some book or anything,I'd be thankful.

Nevertheless,my problem is approaching to girls.Even though I know a lot about that kind of stuff,something always brakes me.I can't approach them.When I talk to them,my mind be like:"she's not interested" or I simply feel so stiff.
Even though I have some knowledge,I always think that something is missing here,but I'don't know what.