Instruct: Classify the given Amazon review as either positive or negative.
Query: Brilliant Reference Book

No other book is needed than this abundant source of answers. The scope goes beyond what one can usually obtain from other books of this nature. I imagine it's indispensable for authors and wish that it were for reference librarians. (Based on their answers, I don't believe that to be the case.) Although not laid out as a textbook, it IS a textbook -the most comprehensive that I've yet seen.