Full text
PDFPage 215
. 1970 Jun;34(2):215. doi: 10.1128/br.34.2.215-215.1970
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.