Power Search allows you running complex queries.

When you enter a query with multiple words, Power Serach will try to find all of the books that
contain all of your query words. However, it won't be a phrase search, i.e. your query words might
appear in different parts of the text.
If you wish to search for a particular phrase, put it in double quotes.
    Example: "independence day"

If you need to exclude documents containing specific word, prepend it with a minus sign.
    Example: good -bad

To find books containing any of given words, use | operator (which means OR).
    Example: good | bad

You can write complex expression by using round brackets.
    Example: (good | bad) pizza

Power Search supports wildcard search with * (any number of characters) and ? (one character) symbols.
    Example: math*

It's possible to write even more complex queries by using regular expressions put in forward slashes:
    Example: /14[1-2][0-9]/ renaissance
