What exactly do you want a link to? I just used my friend's old maths books from high school (he did all 7 courses available, which means about 25% of his 3 year HS studies. It includes stuff like linear algebra and linear optimization and game theory. ) and lots of time.
He went on to become a PhD in maths and just pointed me in the right direction when I couldn't figure stuff out myself.
He went on to become a PhD in maths and just pointed me in the right direction when I couldn't figure stuff out myself.