Full text
PDFPage 791-794
. 1982 Mar 13;284(6318):791–793. doi: 10.1136/bmj.284.6318.791
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.