To search within a website using google, use the site:command (no space after the colon, it is followed immediately by the web address). For example, to search within the Smithsonian website for banjo information, Google: banjo site:si.edu
Use a whole web address to search narrow, use less to search broad. For example:
dulcimer site:www.folkways.si.edu
searches only the Smithsonian Folkways Institute website
dulcimer site:si.edu
searches all Smithsonian institutes and museums
dulcimer site:.edu
searches all education websites, including colleges, universities, schools etc.
