Google Scholar: searches across all Mayo Clinic Libraries' databases simultaneously. Start at the Mayo Clinic Libraries' website and you can link from Google Scholar to full-text of articles to which Mayo Clinic Libraries subscribes or which are free. Click the "Full text SFX" link to the right of each search result. This may not be available on some results.
Search for organizations site:.org
Search for government websites site:.gov
Retrieve a particular file type. For example PDF's, filetype:pdf
Put -(minus sign) in front of a word you want to leave out. For example, mexico -new
Put a word or phrase inside quotes. For example, "health analytics"
Try the Advanced Search to apply multiple limits simultaneously: https://www.google.com/advanced_search