Full text
PDF
editorial . 1990 Sep 15;301(6751):501–502. doi: 10.1136/bmj.301.6751.501
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.