I needed this book for one of my courses. I can't believe I paid 130$ for this atrocious book. There are tons of numerical and typing errors. You couldn't understand anything because there were spelling mistakes in every sentence. I also disliked the explanations in the book. They don't help you out at all when it was time to do the problems. Even the questions were filled with errors such as missing symbols, wrong numerical values (and the list goes on). My prof gave me an errata sheet that had the corrections. It was 25 pages long! I want this Rizzoni guy to give me my money back, not to mention an apology for wasting my time. BUYER BEWARE