I'm a high school student who just finished elementary school.Though since I was into math I started going through advanced math while I was in elementary school and I pretty much finished most of the high school material and I would like to continue with more advanced material like ones on the math olympiads,more advanced and harder problems,and more advanced theorem material.As for now I mostly did trigonometric functions,number theory,math induction,extrema(using derivatives),logarithmic equations,polynomials(in a small portion),series(convergence and recurrence),limits(properties,few theorems),diophante(well only those on math competitions).But I would like to know about things like that odd polynomials must have real roots,or Euler and Fermats theorem,properties of rings and fields and etc. I just don't know where I could find such material,that would expand my knowledge on those themes taught in high school but on a more advanced level that is still fit for a high school student.
ADDED: I did read a lot of material my self,I couldn't find a fitting book.I find most of the problems just easy to solve,I do not even have to use my pencil for doing it and feel pretty bored reading theory material that I all ready know and which is too long for such a simple thing.I would like just a simple stating of the theorem and one a bit harder example done using the theorem,I liked this page for functional equations http://imomath.com/index.php?options=338&lmm=0 maybe with a little bit more theory material(not necessarily),though that site is quite alright I feel lack of material,as that only good material they got is functional equations