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.
Citation gap. (A) Citation density (full count) by fraction of authors, stratified by 5-y intervals. The x axis is on a logarithmic scale. (B) Gini coefficients of citation density (full count) by percentile rank, per year, from 2000 to 2015.