Unless you have a degree in Physics then this book is essential, the maths is the bit that I found hardest, but study maths you must in order to understand radio at this level. I can't imagine how you can get through the exam without it, and the book is not perfect, but it does have 99% of what you need to know, except I was asked a question about the "Wheatstone bridge" in my exam, and the book has no reference that I can see.
Always bear in mind that in the advanced exam, they can ask you questions from foundation and intermmediate level also!
Good Luck 73 de Roger M0HRR