Figure 4.
A returned keyword search may be refined using the Search Options, where returned links may be refined to include or exclude all tools, resources and databases.
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.