An official website of the United States government
The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before
sharing sensitive information, make sure you’re on a federal
government site.
The site is secure.
The https:// ensures that you are connecting to the
official website and that any information you provide is encrypted
and transmitted securely.
Mellon AF, Appleton RE, Gardner-Medwin D, Aynsley-Green A.Mellon AF, et al.Dev Med Child Neurol. 1991 Feb;33(2):158-61. doi: 10.1111/j.1469-8749.1991.tb05095.x.Dev Med Child Neurol. 1991.PMID: 2015984