Full Text
The Full Text of this article is available as a PDF (103.4 KB).
. 2002 Mar;86(2):F135–F136. doi: 10.1136/fn.86.2.F135
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.