Full text
PDFPage 128
letter . 1991 Feb;75(2):128. doi: 10.1136/bjo.75.2.128
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.