I am trying to dig deep into classical mechanics. Among many suggestions, this was an odd one to me. I know of Arnold Sommerfeld and his work, but I have not read any of his works(books, papers, .etc). I tried to find reviews of this book online to no avail. If there are people who have read the book, may I ask you to give me a brief review? What inclinations and school of thought does Sommerfeld adhere to? I have gone through the book, its chapters but I thought I'd get some opinions before I begin studying it in detail. I thank all responses in advance.