Instruct: Classify Amazon reviews into positive or negative sentiment
Query: What a terrible book.

On my age (almost 70 years) and after reading hundreds articles and an awfull lot books about Discus, I finally decided to buy this book. I've read a lot of postings made by Mr. Quarles in several forums and this man gave me the chills. Probably this man is very frustrated and now he has started to offend people very very much. The book is in one word worthless. That's probably the reason of the joker price now asked for this "book". It's nothing worth. Perhaps it won't even light my fireplace. My advice for people who want to start discus start buying books from good authors like Bernd Degen or Jack Wattley.