Instruct: Classify an Amazon review as either positive or negative.
Query: Fair warning

If you buy this book new from Amazon, you will probably end up on the author's email list where you will be subjected to his spam for years to come. My repeated requests to be removed have been in vain and have forever erased any worth that may have been found in the pages of this marginal work. If you still want a copy, buy it here used and save yourself from the spam at least. In fact, my spam-free copy is available for sale at a steep discount.