Instruct: Classify Amazon reviews into positive or negative sentiment
Query: A very useful book to have

I am quite happy with my purchase of this book and Eric Tyson has done a good job at giving us some very interesting alternatives.However, I'd like to recommend that you also pick up a copy of Untapped Wealth Discovered by Jeff Marquis & Kerry Harrison.This book gives us a fresh new approach to realism, has suggestions for reducing costs and increasing revenues, and has an eye for booming markets.Hats off though to Mr Tyson.