Instruct: Classify Amazon reviews into positive or negative sentiment
Query: A very large book and too expensive, up-date it is hard...

This was an excellente book while the web did not exist, when there were 2 volumes and its cost was $250, but now with the web( that makes easier the chance to reviews)it is not that good. The other matter is that a group of orthopaedist have revised the last 4 editions and there are many things that the editor made as mistake, for instance when a technic is described some times the text says "see the anterior edition" (?). That is not good for a very expensive book. Now in this world of the internet we need shorter books and maybe with some kind of year book for up-date the text.