Good calculus exercises/problems?

I can't enroll in a university this year, so I'm studying calculus at home, but the only exercises about calculus that I find are the easy ones. Do you know a great page where I can find not only calculus exercises, but problems as well?

I want to find about:

• hard limits,
• derivatives and integrals,
• and some problems

Barring any more information, I'd suggest you acquire Michael Spivak's Calculus, and begin working your way through the material. There are plenty of exercises and examples, but you'll also deepen your conceptual understanding at the same time, which will help ensure the material "sticks with you" over the long-run, which I presume is a goal of yours, as you seem committed to enrolling at a university, perhaps even to pursuing math, and/or math-related fields.

Spivak will prepare you well.

Shaum's Outline Calculus Problems

http://www.amazon.com/Schaums-000-Solved-Problems-Calculus/dp/0071635343

Try this book

B. P. Demidovich: Problems in mathematical analysis

There are lots of exercises that are hard and beautiful.