An official website of the United States government
Here's how you know
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.
Information on TEK has been organized by continent/area. In cases where research is about multiple countries or no particular country, please see International, Across Borders. To see who has used TEK and how it has been used, please click on the following pages to access examples: