I bought these cards for my ap world history class because they were required. I really didn't use them that much because they aren't very good. I love flash cards I make them for everything! But this is not a very good product. I didn't like this review book either. If you want to learn something and have a good study tool for your ap world history class buy http://www.amazon.com/Cracking-World-History-College-Preparation/dp/0375429956/ref=sr_1_1?ie=UTF8&s=books&qid=1283638171&sr=8-1 Its the best!