A relative of mine who took CIE A Level Maths last year kindly gave me all his books for free. I'm registered to take Edexcel International AS Level Maths next year, and I'm studying with a tutor, so I need to get the resources on my own. (I'm not in a sixth form college.) Money is a bit tight, so I'd just like to stick to the resources I have if possible. Would I be missing anything or at a disadvantage if I studied with CIE books?