Instruct: Classify a given review into positive or negative sentiment.
Query: An invaluable reference

Having been a collector of Soviet militaria since 1993, I have yet to find a more complete, fact-filled book than this one. No other book, including Russian publications, even comes close. Close up photos, front and back, showing every variant of every Soviet order or medal make this "the" book for collectors. Photos and tips on how to spot fakes are provided throughout, as well.It's expensive and can be difficult to find, but well worth it.