Option 1: Use Advanced Search
Look for the "site or domain" box in Google's Advanced Search options and enter the domain you'd like to search, as shown below.
Option 2: Add "site:-"
You can also do this by adding site:.edu (or .org, .gov, etc) to the end of your search terms in any Google search box. For example, to find articles about “ethical leadership” published on government websites, enter the terms "ethical leadership" site:.gov, as shown below.