The content is available as a PDF (210.2 KB).
letter . 2013 Apr 5;30(1):70. [Article in Spanish] doi: 10.1016/S0212-6567(02)78968-3
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.