Full text
PDFPage 478
letter . 1981 Feb 7;282(6262):478. doi: 10.1136/bmj.282.6262.478
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.
