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.
The thickness and gray level of links is proportional to the logarithm of the weight of the link. Links are labeled according to the weight. The color of vertices is according to the economic sector of activity.
