This is Vol.5 of the Course of Theoretical Physics
This book is not required , and the course will
not follow it (or any other text) closely. If you want to buy a single book on
the subject to use with this course and don't have a favorite yet, this would be
the instructor's choice. It's also an excellent reference that you'll be likely
to use for as long as you stay in physics. However, if you like a different book
better, choose that.