New maths subjects?

Could number theory, set theory, group theory and other advanced areas of math be added as subjects?.

I am currently trying to learn maths with the hope to get a phd and become a research scientist in the subject but can't find a book with it all in one place.I recently found your website and think it is really helpful but does not contain subjects on all areas of maths so i was wondering if you would be able to add them.