You can study using only Bristol. This being said, there are lot of questions you might have no clue as to the answer they came up with unless you plunge in the books. You will face some topics also you may have never seen before. Everything is based on the RAF.

If you start the navigation subject, make sure to not use the E6-B or CR-3. You won't find the answers. They are so close together. It took me a long time to realize this. You will need to use the CRP-5 - the UK version if you wish.