Full text
PDF
. 1913 Jun 7;1(2736):1193–1196. doi: 10.1136/bmj.1.2736.1193
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.