Use quotation marks to search for your terms as an exact phrase. Great for title searches.
"capital in the twenty-first century"
AND, OR, and NOT must be in all caps to be recognized as operators.
NSA OR "National Security Agency"
cellular NOT phone
Use parentheses to define the order of operations.
("Affordable Care Act" OR Obamacare) AND "birth control"
? matches a single character and * matches multiple characters.