In my opinion, I felt the best book to study federal law was this book called "Guide to Federal Pharmacy Law, 8th Ed. By Reiss. It's easy to understand and there are lots of questions throughout the book and at the end of the book to help you understand the chapters. I bought the book and it was very helpful because I find law so dry. I get sleepy after reading 2 pages but with this book I was able to get through a lot. It's $50 but well worth it. I hope this helps. All the best.