Full text
PDFPage 451
. 1967 Mar;15(2):451. doi: 10.1128/am.15.2.451-.1967
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.