Full text
PDFPage 1622
letter . 1978 Jun 17;1(6127):1622–1623. doi: 10.1136/bmj.1.6127.1622-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.