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.
(a) Graph layout of the whole network, with red nodes representing a chosen fraction of the most highly connected core, and blue ones the periphery, for 
, a control propagation value of 
, 
and 
; (b) Subgraph of the most powerful companies with 
(about 100). The node colors and sizes correspond to the 
values.
