Full text
PDFPage 792
. 1968 May;16(5):792. doi: 10.1128/am.16.5.792-.1968
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.
