AP Euro Prep Books

I’m going to take AP European History at school next year, and I was wondering which prep books are most helpful for the course? Thanks!

Princeton Review and Barrons

Here are some web resources:

http://thecaveonline.com/APEH/studyguide.html
http://www.historyteacher.net/EuroProjects/ExamReviewSheets/APEuroMainReviewPage.htm