Anywhere you see the general search box, you will see a link to the advanced search. Advanced search gives you several options to make your search more specific. You can choose to include or include materials based on their author, title, subject, keyword, format, library location, language or year. You can add multiple "and," "or" or "not" lines by clicking the buttons for those words.
For example, if you wanted to see works by an author with the last name "Farmer," you may want to use an advanced search to weed out results for the keyword related to the occupation.