Full text
PDFPage 688
. 1975 Jun 21;2(5972):UNKNOWN. doi: 10.1136/bmj.2.5972.unknown
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.