Instruct: Classify a given review into positive or negative sentiment.
Query: Absolutely amazing

An exceptional book, analyzing in detail all aspects related to the Allison in-line fighter engines: design, production, aircraft which used them, installation, performance, etc. Of particular interest a comparison with its major competitor, the Rolls Royce Merlin.A great book for enthusiast, but not everybody will be so interested in the details of an engine to buy such an expensive book, which is worth its value and more for the really determined enthusiast.