Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Pocket Companion as a good review, esp. before you sleep!!

This pocket companion serves as a concise overview of the most important facts & concepts from the parent textbook (Guyton's Textbook of Medical Physiology). However, it does not contain all the details or some clinical relevances, that's why you have to go back to the parent textbok for furthur info.