Ok, so I am just ending my first freshman semester at college. I took two years of calculus and physics in high school and got 5's on the AP tests for Physics C and Calculus BC. So, when I got to college, I was placed into Calc III and Into to Modern Physics. They've been great classes, and even without the rigorous calculus training from college, I've done outstandingly well in both classes. The only thing that I regret is not having are my own introductory books for calculus and physics so that I could look through them for reference, because I had to use the school's books when I was in high school. I was wondering what books I should get to keep and use as reference for the future. I used Stewart's calculus books and Halliday's physics books in high school, and thought they were ok, but not great. I've already had extensive training in physics and calculus, so what kind of books should I get just for reference? I was thinking like Apostol for calculus, but they run kind of expensive. What do y'all think?