Full text
PDFPage 945
letter . 1990 Apr 7;300(6729):945. doi: 10.1136/bmj.300.6729.945-a
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.