Instruct: Classify Amazon reviews into positive or negative sentiment
Query: The best reference on the subject

The book truly deserves praise. The most wanted quality of a reference is its completeness. I assure you: there are NO entries missing. Places, people, topics and events are ALL present. There are many cross-references that help you find more about a specific subject. I've been in Sciences for quite a few years and read intensively. In many books I've read, the index is often weak and incomplete. As an index, the book fulfills my wishes, everything is there. Furthermore all entries receive a complete description and explains relationships with other subjects. This work is apparently a Ph.D., well it certainly deserves the title.