Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Do not buy this book

I am a PhD student, and had to buy this book because it is the textbook for the "Advanced Semiconductor Devices" course.The book has been nothing but a pain in the neck. The equations are not properly derived, there is insufficient information given for students to be able to solve the problems given at the end of the chapters.The author frequently introduces new variables, and describes them with an equation without giving any idea of where that equation is coming from.Do not buy this book. Im sure any other book would be alot better. If this is the textbook for your class, then I guess you are forced to buy it. Best of luck!