Full text
PDF
letter . 1985 Apr 6;290(6474):1076–1077. doi: 10.1136/bmj.290.6474.1076-c
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.