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.
Visualization based on co-citation network: The nodes represent the authors. The radius of circles is in proportion to the amount of literature of the category, the larger the node, The larger the node, the more frequently it is referenced. Important nodes are highlighted with purple rings.
