AP Calculus Preparation

[drosser]

What is the best prep book (hardest) for AP calculus exam? Is it Princeton Review or Barron's? Are there better books?

[mathwonk]

i recommend first learning the material, then buying a book of actual old ap tests.

[drosser]

I've already learned the material. I'm just asking what book is the best to give sample problems that are equivalent to the questions on the exam.